Usually regiments are quicker to get from class 3 to 2 but battalion has more places they go on exercise. Again personal preference if you want to stay in one place all the time and work your way up or go different places but work up a little slower. Camps also dictate what aircraft you want to work on. So wattisham has Apache, Ireland has gazelle and fixed wing, Yeovil has wildcat.
Every camp has pros and cons. From Ireland having a dirt cheap bar like 50p a vodka and a burger van on camp. Wattisham has lots of sports the bar and shop aren’t too bad plus the surrounding areas has more or less everything you need. Sorry I don’t know much about Yeovil as I don’t plan on going there.
Ireland and wattishams blocks are a little old but at the end of the day it’s still single man. If you’re at lyneham the now it’s still better than 4 man rooms