I don't have a sevastopool, but I've fought against many in GBs. The extra support slot is certainly nice. But in a 1v1 match, I think Colorado would have a fair chance. And the South Dakota is a better ship, having better range and speed. If you can get it, the Maryland at 77 is much better than Sevastapool. It's just as fast (or faster, I don't know speed cap of Seva), have much more firepower and more range. It's also at Lvl 77 so you loose less exp when leveling past 80 to Iowa. All for the same number of support slots. But if you like Sevastapool, you can certainly use it till Iowa. One thing to caution is that for Iowa and Montana, you will be using 45 deg guns, I don't know what the gun angle for Sevastapool is, but it might be a hard adjustment to 45 deg guns. 

One question out of curiosity, you made a scout out of a Hero sailor. Can I ask why?

The USN Sevastopol goes up to 42, making it faster than the Maryland. Sorry.

The penalty for having a ship well below the crew is also largely negated if you're good because the EXP bonus for hitting BB4+ is far greater than the penalty (still only a 10% reduction 24 levels above ship, and Iowa is 28). The Maryland only gets that bonus on BB5+, so in some cases results in less experience for the same damage.

OTOH, the Maryland is fun and hits very, very hard, something the Seva can only dream of. If you can get both, get both. They're both go-to leveling ships for the USN, but they're different and neither is that much superior. Using regular tree ships is more a question of wanting to experience them and personal taste - USN BB1-3 aren't so hot at level, but great fun with high level crews.

I'm also interested as to why, of all sailors, the scout is the hero one... :-)

I vote for the Maryland.     As noted, it hits hard and I believe it is a better BB then the Iowa.
I've got both and I like the Maryland better.   It may be a little shorter range then the
Iowa long range guns, but they throw a lot more shells. 

The long range guns for the Iowa, are darn near the worst for accuracy of all USN guns.
They have a high dispersion factor.  In other words, they don't group well even with high lvl accuracy gunners.     The length of the Iowa requires a little more finesse in aiming.

The Maryland, on the other hand, has one more turret then the Iowa so it throws a very large salvo.   Being shorter length then the Iowa, it is easier to aim and concentrate firepower.   The only weakness is that it has a slightly shorter range then the Iowa.

Another weakness, if you can call it that, is its "coloration".     Since it is an eyecatcher in a battle group, CV drivers tend to attack it with DBs or TBs and ignore more powerful BBs.

Many times I've been out of range in the rear of a battle group and been repeatdly attacked by aircraft while the main line is fully engaged. 

I have never gotten a sevastopol, so I can't say for certain who good or bad it is...but I know I can sink them with the Maryland.

Seve can go to 44 knts^^

After awhile I found it kinda boring playing the same ship for awhile.
So I went SoDak and I loved it.
SoDak has good speed and does some good damage :) 

Downside? It's a bit fat, so you need to twist your ship a bit more... (You need to do this with all ships anyway*_*)
My spread wasn't that bad for at level gunners, was able to do some good games with it. 

After hitting level 89 you should definitely go for the Iowa. It's a great battleship, because of it's hitbox. It's a beauty too! I never possessed a Maryland, I only know that it's quite easy to sink. Just outrange it.

Don't forget to twist (dodge) :) 

oh and i did class my T slots as reload first and then back to acc to see what that would do.