Feral gets better once you get better gear.
The biggest issue with solo play is that you have to spam Mangle, which isn't as effective as Shred, especially on longer fights. On the other hand, with some points in Thick Hide (even in full DPS spec, I dump three points there, in case I have to off-tank), we can pull a bunch of mobs and rip them apart in Bear Form.
We lack burst, but can keep up the damage without relying on cooldowns. Berserk is just one of those things I pop when I feel I've got my buffs and debuffs rolling and want to spam Shred some.
____________________________Please "talk up" if your comprehension white-shifts. I will use simple-happy language-words to help you understand.