I have had as good or better results with them as I do with Kinetik
I use them in every install now
in fact I have a customer with a 99 Quadcab f150 that had 3- 250 amp mechman alts take a crap on him in less than 1 yr trying to push 1 deka 31 and a brutus 2400d amp so we went back to the original stock alt ( 135 amp ) and 3 of the BT120 batts and he maintains 12.7+ volts at all times.. and has not had a single electrical problem since...
( and my prices are as cheap or cheaper than that egay link you posted and IIRC so is Sonics ...)