Most of the reviews I read said the RK pellets burn with a lot of ash, not much smoke and flavor and wild temperature swings. I emailed Lumber Jack about making pellets for RK and they never returned my message. Other people said they have called LJ and they said they Did Not make the RK pellets.
Buy the Bullseye. I have both and love them. I use the 1250 mostly for my long cooks (butts, brisket) and when I need to feed a lot of people. I will usually run the 1250 all night on my long cooks and monitor it with my phone.
I am using Lumber Jack pellets right now. Rural King stopped selling them. I refuse to use RK brand (read the reviews). I highly recommend Pit Boss competition blend available at Lowes, Menards and others.