I 100% of the time use IRs for all my guitar presets...bass that's a different story. Most of the time I don't even use a cab with my bass presets.
I think if you find the tones or artists you like, find out what cabs they use, get some good IRs of the same cabs and roll with it. To my ears IRs always sound better.
Just my 2 cents.
Just don't go crazy buying them because you can end up spending a lot of money and not using 90% of them.
I can recommend York Audio's Mesa OS cabs, Ownhammer Heavy Hitters, and GGD makes some plugins that you can export your own creations.
Also, there are a lot of good ones for free too online if you look around. Maybe try here first: