saw a Columbia EPX T1 on ebay and was wondering how good can an epoxy cover be.
The epoxy cover is very unique. It has pores (caverns really) that are much larger than a regular particle or reactive resin. It has a weird chemical smell (not too pleasant) and it soaks up an INSANE amount of oil which will cause it to darken up quickly. I am guessing that it creates it friction from the caverns acting like suction cups on the lane, but I could be wrong. Some early batches of EPX T1s were so brittle that they were known to detonate on impact with the pins.
As far as the reaction goes, the strength in oil depends on the batch. Some are easily as strong as the earliest high load particle balls but some seem to be much tamer. It does not really react like any particle ball. Particle balls will rev up hard/roll out/stand up in friction. The EPX T1 looks like a pissed the **** off urethane curving into the pocket. It starts burning rotation early but it retains it throughout the lane (continuous). The only particle ball I know that I know that had a very slow continuation was the Visionary Midnight Scorcher (urethane particle) and to a lessor extent, the Storm La Nina. The EPX T1 is still more continuous than both on high volume patterns with the same surface (burgundy scotch brite). The EPX T1 and Scorcher completely beats out the La Nina on floods.
It is a crap shoot due to issue with some of the batches but if you want smooth continuation and you are willing to take a risk, there is absolutely no better coverstock than epoxy.