Shooting off the bench, I really like thumbhole stocks, but for hunting, they don't handle as well as a conventional stock for me. To bring one up without taking my eye off the game, I have to fiddle with it trying to get my hand in the right place and get my thumb into the hole. It's distracting, and has made me look down when I didn't want to. Also, it's usually awkward or uncomfortable for me to keep my hand and thumb in place on the stock while walking (or even sitting).
I have had several thumbholes, but haven't kept any of them. There is one other observation; straight comb stocks on hard kicking guns make my cheekbone sore. Stocks with Monte Carlo cheekpieces don't. I had a thumbhole stock that had a Monte Carlo cheekpiece on it that was maybe the most comfortable stock to shoot that I ever had, but didn't work for me on a hunting rifle.
My opinion, (confused by age and experience) Tom
Texas State Rifle Association Life Member
NRA Endowment Life Member
A big fast bullet will beat a little fast bullet every time