Funniest thing is you don’t actually know what you would like to drive until you actually drive them. For example when applying to my TOC I was so excited at the prospect of driving the great looking 707 stock, however the idea of 455/456 didn’t appeal to me much. Now tables have massively turned and I so much prefer driving 455 stock to 707s. Each stock has such different characteristics that you just won’t know.
As Big All said above variety is great, even a stock you really hate driving is nice to drive after driving different ones. However a TOC with say only 1 traction to sign (are there any?), if a driver realllyyy did not like that stock I’d dare to think perhaps that’s a reason they may want to move, but even then it would’t be for a reason like they just don’t like driving it but perhaps that stock has no air con and the driver is dreading yet another heatwave. Drivers moving TOCS are usually to do with location, terms and conditions, salary etc. What stock they will be driving is usually bottom of the list if even on the list at all.