1. Yes XXI was rockat fats with max underwater speed 16knots (can mantani less the one hour) which is same as Apolllo V rocket (28800 km/h) or basic unguided WWII missile (290-330 m/s). (In RL XXI have 3-4 times greater eco speed and greater endurace in eco speed). In game XXI speed is 24/40 and 21/34 which is fastest SS6. What do you what 50/90 or something ridiculus ?

To be serius may by switch the speed will be good. surface 21/34 undervater 24/40, but with that mean when you catch BB than BB4 and above it cant escape (with exception of WAW).

2. KM SS6 have best reload from all SS5-6, have 6 proxi torpedos, with send fasted torpedo (60kn) and 3rd greates dmg per torpedo ? Plese which partameter you wat better to have some belance ? (Becase in SS is rather less balance first 4 natiins in SS1-4 have some balnce but when arrive nev nations ans SS the balnce is losing).

3. Max deph have great problem in NF which knowe only 3 levels, surface,periscop depth, and critical (where you are invicible to all undervater attck which in RL uo was not. End war deep charges has ability to archive 300m which is tipical crit dive of ingame sub). 

4. At the end you have good turnforce on SS6, dot forget that SS balance create SS4 best turnrete subs, SS5,6 have more suport slots (ie. greater oh time,better reair ability easy SD cap archivment).

5. To crit time I cant compare but I thig that all SS tier heve same time or very minor diferences.

Still thing that UK  SS5 was much greater disaster and XXI is still beter then IJN SS5. I thing that greatest problem is that XXI is only front fighting SS which you are not use to use. (But i thing if enemy sip is behind my SS tha I make great error).

uk subs win km sub in ww2 lol top10 german commanders sunk more ships than whole uk submarine force

Look what Winston Churchill sayed Uk ldr tell all i dont nead to explain more listen hes words

Winston Churchill once wrote that, '... the only thing that ever really frightened me during the war was the U-boat peril'. In saying this, he correctly identified the importance of the threat posed during World War Two by German submarines (the 'Unterseeboot') to the Atlantic lifeline. This lifeline was Britain's 'centre of gravity' - the loss of which would probably have led to wholesale defeat in the war.

equipment from North America to Britain, the outcome of World War Two could have been radically different. Britain might have been starved into submission, and her armies would not have been equipped with American-built tanks and vehicles.

Moreover, if the Allies had not been able to move ships about the North Atlantic, it would have been impossible to project British and American land forces ashore in the Mediterranean theatres or on D-Day. Germany's best hope of defeating Britain lay in winning what Churchill christened the 'Battle of the Atlantic'.

http://www.bbc.co.uk/history/worldwars/wwtwo/battle_atlantic_01.shtml 

If germans was more clever they will change enigma books before every u boat war patrol and germany will win war , on this way alied know all time where german uboats are 
Allied could read enigma in 1941 than germans put 4th rotor in enigma(1942) and was again in allied control from 1943 to the end of war

Many uboot crews lost thier life becouse high command didnt listen uboot commanders that allies read thier massages 


And for other nation subs 
Translate this seams like you dont understend english or you just troll around
UK ss5 is disaster but i dont play it and i dont care to search history facts for sub which i dont play let it do players which use it , i fight for ships which i use i dont have time for all

All real life facts for any nation have my bless but i will not waste my time to reserch it  

You have one serius problem and it is known as a propaganda to KM ships. You forggot some importnot fact, KM use and lost more subs then all Allied navy to gether. Yes Km subs sunk great amount of merchmant ship abaut 14.5 mil brt. But you dont ask ONE importnt question "Why ?" First the easiest answer is becase Allies have this amout of ships. From the ability to sung mechmant ships you think that KM sub is Uber and rest of world has useless sub. But tru is that typ VII and IX heve only one parameter excepional and this wad submerged depth. Rest of prarameres was avarege with all WWII sub. Ifg we look on KM sub first exceptional sub was type XXI and XXIII which was revulution subs in design as a full under water operation.

From last sentece i fell from you some ignorace and hoples pride on that all KM must be best. You have best renge on BB, best demage on fighterse best turnrate on all subs and you want also best demage per voley on sub ? May be you need to crete KMfield not Navy field.

It need osme time to found hov meny players will hate XXI and how many will love it. From the other coment XXI hate players who relay on back torpedos.

uk subs win km sub in ww2 lol top10 german commanders sunk more ships than whole uk submarine force

give and me the name km comander who sunk 1 uk ss...

HMS Venturer sunk U-864  Type IX U-boat She also sank U-771

:))) so who was best ss hunter in rl ww2

On 6 February 1945, U-864 passed through the Fedje area without being detected, but on 9 February Venturer heard U-864's engine noise. Launders had decided not to use ASDIC since it would betray his position and spotted the U-boat's periscope as her captain looked for his escort. In an unusually long engagement for a submarine, and in a situation for which neither crew had been trained, Launders waited 45 minutes after first contact before going to action stations. Launders was waiting for U-864 to surface and thus present an easier target. Upon realising they were being followed by the British submarine and that their escort had still not arrived, U-864 zig-zagged underwater in attempted evasive manoeuvres, with each submarine occasionally risking raising her periscope.

Venturer had only eight torpedoes as opposed to the 22 carried by U-864. After three hours Launders decided to make a prediction of U-864's zig-zag, and released a spread of his torpedoes into its predicted course. This manual computation of a firing solution against a three-dimensionally manoeuvring target was the first occasion on which techniques were used and became the basis of modern computer-based torpedo targeting systems. Prior to this attack, no target had been sunk by torpedo where the firing ship had to consider the target's position in three dimensional terms, where the depth of the target was variable and not a fixed value. The computation thus differs fundamentally from those performed by analogue torpedo fire-control computers which regarded the target in strictly 2D terms with a constant depth determined by the target's draft.

The torpedoes were released in 17 second intervals beginning at 12:12, and all taking four minutes to reach their target. Launders then dived Venturer suddenly to evade any retaliation. U-864 heard the torpedoes coming, dived deeper, and turned away to avoid them. The first three torpedoes were avoided, but U-864 unknowingly steering into the path of the fourth. Exploding, U-864 split in two, and sank with all hands coming to rest more than 150 m (500 ft) below the surface.

She also sank U-771 on 11 November 1944 7 nautical miles (13 km) east of Andenes, Norway, off the Lofoten Islands.