I have both. The Timmy is my all time fave low gain power amp style overdrive with British amps. The RC Booster is one of my favourites used as an almost clean boost.
The RC can be a little more tone neutral.
Timmy a bit more vibey and exciting.
Timmy has more gain on tap-it'll go to mid-gain overdrive.
definitely the Timmy over the RC booster. both pedals are amazing, but the timmy is much more transparent and versatile. i've also had both twice, and the timmy has always outshined the RC even simply as a clean boost.
Ive had both... sold the rc. There was something about the gain on the Rc... transistor sounding?? Something...
If you only want clean, get the bjf sea blue eq ( from what Ive heard ), but if you want some grit/gain then the timmy. With the right chip in it you can nail it down man.
I have both and IMHO they are not comparable so no decision to be made. Th RC is an almost totally clean boost. You've really got to crank the gain to get any od at all with single coils. The Timmy is an OD but a lower gain one. It can be goosed into a bit higher gain but that's not it's sweet spot. However put the RC in front of the Timmy and you can extend the gain range of the Timmy a good deal. It's one of my favorite combo's.