the front and rear tires are different brands.... the front is a Tioga and the back is a Serf... their tread patterns suit the arrangement....
there are 50 studs per tire (although there is room for 50 more studs too. the guys at Alter Ego were pretty cool and may add the additional 50 studs if requested...)
these are not like the studs in the nokians or schwabbe or innova... THOSE studs are little nail-like tips/points and are primarily made of steel... THESE studs are the HEAD of a carbide screw, which has 2 crazy-sharp edges that are roughly a 1/4"... so instead of one little dinky point you get 2 sharp 1/4" edges per stud... maybe i can get a picture and post it
the studs are screwed into a knob that runs along the edge of the tread pattern, so it doesn't wear on pavement and slow you down on smooth days, although you can still hear them a little... especially on corners... and can deflate PSi to give more contact
i think they're awesome....
somebody else buy some to confirm my conclusion!!!

in terms of which tire to put where in terms of stud count.... i would guess that the higher the stud count the better it would be on the front rim.... other people may have different opinions though....

J