I've bought a Selmer C* with Rovner Lig and some 2 1/2 reeds.
If I play with no.2 reeds the sound is much deeper and seems very throaty, kind of more resonance there.
Its very nice, but gadzukes it takes some puff!
I thought a new mouthpiece would make things easier!
I think the sound is worth the extra effort, but has anyone else found this to be the case?

You've got the wrong mouthpiece then - the difference between the C, C* C** and D (the most common 4 Selmers) are the top opening, and wider tip openings take it out of you quicker, or perhaps maybe you just don't suit the C*