Xylia
Terrarian
I've never used a crimson world for a playthrough, so I always get molten armor and the fiery greatsword. But yes, it is lackluster compared to the other "major" biomes like the corruption, underground, and hallow.
Crimson Armor has like 2 or 3 less defense, and a bit less melee damage, but yet greatly increased life regen. That's why most players skip Molten Armor if they have a Crimson world. And now with the Cascade yo-yo, a lot of players even skip the greatsword too. Especially with the Hellwing Bow being such an awesome weapon to use against the WoF (Cascade ain't exactly shabby either once you kill the hungries).