It was almost by accident that I tried a Best Brass Trumpet mouthpiece - but as a result I started to look at their website!
This mouthpiece is my dream come true... it has the large rim size that I like, and a medium cup, but with the "accelerator" it actually gives a boost to my range, while allowing me to have the tone that I want.
Pros: fantastic mouthpiece, superb tone, perfect rim, improved higher range, very easy playing (less effort), better endurance (for longer)
Cons: not for everyone (but if you like a large rim, it could be for you), some have problems adapting to the "accelerator" (but this was easy for me), the price is a bit on the higher side
Conclusions: mouthpiece "safari" ended (I found my dream mouthpiece), so easy to play with much less effort than any other, same rim size for the TP-1X and the FH-1X (for the flugelhorn), so I am so happy to have the exact same feel for all three - this is an incredible mouthpiece and I highly recommend it!
After using this mouthpiece for 3 months now - it keeps getting better and better! I have tried to go back to other mouthpieces, but this one is absolutely the most comfortable and the easiest to play with exactly the sound and tonality that I want. The only other which I now use is the Best Brass trumpet mouthpiece 1X, which has that beautiful flugelhorn like sound.... Wow - I never knew that Best Brass existed - it is a game changer all around!