I've been using it for a while now. I really enjoy the soggyness and feel it adds while mixing. Completely changes the vibe as you go, and makes the process more fun.
Regarding the end product, I'm not entirely sure whether I can objectively say that it's made my work sound any 'better'. Different, for sure, but I'd spent a long time getting familiar with making stuff work ITB. Metal in particular seems not to lose much from ITB if you're after that 'modern' aesthetic, so it could go either way.
Makes mixing rock and other genre projects a hell of a lot more fun though. Everything ends up needing less processing, and you can let the feel guide you rather than playing a numbers game all the way.