As the British Heavy tree is not as popular, interesting as the other tree's available, there isn't a great deal of dedicated information that has been provided. However, a good thread that will help folks would be:
http://forum.worldof...fv215b/#topmost
I'll lob in a few thoughts, just in case (comments are for fully upgraded tanks, stock grinds are just as painful here as elsewhere). For the most part, horrid mobility, workable armor instances, LASER ACCURATE guns with modest alpha output and good ROF.
Churchill 1 - Good speed, decent mobility, workable armor when angled properly, good selection of guns, amazing ROF for its tier, relies more on sniping/tracking/side shots in higher tiers. Horrid gun depression.
Churchill VII - Be advised, this tank has the reputation of being the hardest to get through. Horrid speed/mobility, decent armor that side scrapes well, top guns are good, added health pool helps, at tier 8 though, this tank is best used as a support/TD tanks as an ISU-152 can just about one-shot you. However, this tank teaches invaluable methods that are required to excel at the Black Prince. Cannot flex/escape due to lack of speed. Horrid gun depression.
Black Prince - Horrid speed, but excellent mobility - turret/rotate speed make it almost impossible for a medium to "death-circle", excellent armor, reliably bounces tier 9 guns when angled correctly. Top gun is amazingly accurate and has insane ROF. Low alpha means gun must be singing every time its loaded to stack damage (this is no IS). At tier 7 this thing can get right into the other guys' grill and face-hug them to death. At tier 9, its an excellent support tank that does great flank/rear damage while keeping bigger tanks perma-tracked. Horrid gun depression.
Caernavon - Decent-ish speed/mobility, excels at hull-down tactics as all the hull armor got left behind with the Black Prince. 83mm Type B barrel is excellent at tier 8/9 with this tank being able to burn any other tier 8 into the ground when played correctly, (hull down, abusing ROF/gun depression). At tier 9 becomes a solid support tank (stalking behind that E75 and putting out shots while the E75 reloads), at tier 10, works as a slow-ish medium/3rd line support tank (due to the overmatch of tier 10 guns on its trollish turret and poor hull armor). Show your lower armor to anything and you will pay for it.
Conqueror - That L1A1... Did I mention the 120mm? Have I told you about the gun?? Modest mobility, good gun depression, amazing ROF for its tier and reliable damage output that excels at 2nd line support (hanging out behind that E75/E100) or long range sniper/TD mode. Turret can be troll-ish but RNG is a finicky critter, hull armor is nonexistent at tier 9. At tier 9 this tank, when keeping its hull hidden, is one of the highest DPM tanks on the field and while the alpha isn't amazing, putting a shell out every 9s or so is an amazing thing. Ammo rack damage is a common complaint and armor is an afterthought.
Fv215b - Rear mounted turret will cause brain hurt, as all the tactics used prior to this point no longer apply. While this tank can, and will, sidescrape well, be advised that better players will just shoot out the exposed turret ring just below the gun, effectively taking your gun out of the fight. L1A1 again, but with faster ROF means that this tank has some of the highest DPM in the game. However, from a meta-game perspective you have to be placed properly where you can shoot things and knowledge of weakspots becomes a requirement. Workable health pool (as long as you aren't spotted by any auto-loader), turret can be troll-ish but shouldn't be depended up on with regularity. Ammo rack damage is a common problem reported. Amazing mobility for a heavy, acceleration/hill climbing/terrain resistance are all amazing for a tank this size. However, give this tank a break, as it can take a few hundred games to figure out where to put this thing to make it work. Some players turn the hull around and "back" into position to allow for some gun depression and more range of fire. The best thing about this tank its gun, so 2nd line/long range support are where its at. Low-ish alpha means that the gun needs to be in use often to get decent numbers (this is no Waffle/268/JPzE).
While this line can lead to lower stats (as WN7/WN8 depend on kills/damage output) there are some real gems in this line for the heavy player. However, if you like the speed of the Russian line or the workable armor of the German line, you WILL be disappointed here. If you take this line for what its good at, amazing guns that will spoil you for their ability to fling shells across the field and do damage (try THAT with your 704), instances of amazing armor and tanks that reward the player that can exploit their strengths, there are tanks in this line that will occupy your garage for some time.
This was my first heavy line and I have thousands of games in these tanks (most played tanks are Crvon/Conq). While I'm no ones expert on this game, this line is worth your time. Give it a chance and enjoy the ride!