I´d go for the Epsilon. I just got it myself (not sure when I´ll build it though, but it was on sale locally...) and it´s a bit more modern than the WB60 with more fuselage volume and a redesigned wing for better snaps. I plan to downsize the ailerons and elevator a bit on mine to make it even better for pure pattern style flying. I´ve seen that some people have done this to the WB60 as well.

Also, all the flying qualities aside, the Epsilon just looks so much better.

/Erik