No matter what you read or who tells you want you'll only know if you test it yourself. We did a test and brewed our Fullers ESB clone several times over. It's a great drinkable beer and rather straight forward, we just changed the base. We tried:
Briess 2-Row - standard, leaning towards a pale
Candian 2-Row - ended up with lower OG, less body
Rahr 2-Row - very close to Briess
Optic - odd! not bad but different
Muttons Maris Otter - more body, 'best' tasting one
Of course even making the same beer a few times with the same gear, it's slightly different due to fermentation temps. Anyways it's also how we discovered that different mills (different crushes) affect the beer.
2 LHBS sold us the same grain (Briess) and in making this ESB, the one shop that admitted to having a 'meh' mill (crush never looked very good) always came in 5 to 10 points low on OG, other LHBS has a very nice mill, always hit OG. The place with the 'meh' mill is MUCH cheaper and closer to me, so we bought our own mill and it's all good now.
Something we do to is save a few bottles from each and throw them in the fridge so we can compare them to later batches. Clearly time changes the taste a bit, but we can get a general idea.