SLO - is cool, it's kinda 1 trick pony due to the single tone stack, but definitely has a great sound. It just sounds right for hard rock. You won't even notice how good it is unless there is an other amp nearby for comparison. On the downside the fx loop is a nightmare don't even bother to use it unless it's modded properly. Overpriced.
XTC - good clean but nothing spectacular like an OD100, blue channel is amazing, red is kinda too smooth and compressed, me no likey.
Rockerverb - It sounds great alone, but simply disappears in the mix when the band kicks in. Tried a bunch of them, Thunderverbs, small and big rockerverbs, TH30 all the same.
I would recommend to try the EVH 5150 III. Fairly cheap used, considering the 3 above.Clean channel is ok, nothing special, but turning up the gain past noon, it's instant AC/DC. Blue channel is a mix of the SLO lead and the XTC blue, that channel just kills. From plexi to modded JCM800. Red channel is über gain territory, don't even bother to turn the gain above noon. Works nice for leads. Scooping the mids and turning up the presence, transforms it to one of the most brutal metal amps. Quite picky on cabs, sounds best with it's own cabinet.