+1 on the spec II, probably because its pretty simple, the e-01 seems a bit complex to me, I think it offers some more advanced tuning features (can be integrated with e-manage) and some of those extra gauges that don't really do much but add to the "cool gizmo" effect.

If you JUST want an ebc, go for the spec II, it has a lo and hi boost setting and various other little settings. Its simple, its effective, its good.