I am the only Pentax user on the Photo Society board, and probably the only person who teaches classes that uses Pentax in our region. It's predominantly Canon, but no one holds my choice against me. Reason: either you're capable as a photographer or not...
However, I do think my choice makes them shake their heads and wonder what is possible (if they shot) with another brand...
We do have competitions, but the main attraction is the yearly symposium and monthly classes - part of the $35/year membership.
BTW, if you're willing to travel, there will be Pentax specific promotions this year. Otherwise harangue your local camera shop... it's been brought forward to several folks at Pentax. If you guys start asking, things might happen...
Cheers,
Marc