Been using them for almost 2 years now and havent run GFO since. Avast marine (local to DC area and owners are really into the hobby with one having a green house with 6 500g tubs) sell biopellets and a really good reactor as well.
I was using a TLF 150 at first but things kept clumping up and not working well, switched to their reactor and its been MUCH better. for that matter i think almost all my equipment is from them now (CARx, Skim, Kalk, etc)
the best way to start is with a 5 gal bucket with some water from your most recent water change....throw some in there after letting them soak overnight in some tank water to get all the air out of them and throw in some MicroBacteria7 or something along those lines. i used this to seed the biopellets. in like 5 days it went thru the algea bloom where the water clouds up. let that settle out for a day and then into the tank it went. i didnt see a bloom in the tank and its been running great since.
there is a write up done by Justin (from Avast) that is a really good explanation of the process, email him and im sure he will share.
its nice because you just let them run and dont have to do anything else.
Hopefully ill be down your way in the near future for my blacksburg fix..been too long.