In terms of price the DTXPlorer is quite expensive at around 500-700 for a set.
the RR drums are kind of funky and are uncomfortable to try if you actually like to drum. the DM KOC are not to bad.
The GH:WT from what I understand are going to be recalled due to craftmanship issues, those pads broke down on us in 30 mins.
for the price and quality and ability to convert to a real drum set without the huge price tag, I like the Ion Set a lot.
they take a hell of a beating as well.
and are compatible with RB1 RB2 and GH:WT. we used them on a Drum Mania as well since its all USB but did not review the set fully on that title on a PS2. We were using an Ion Electronic Drum Kit
HERE
But those pads left a lot to be desired in terms of durablity.
299.99 for an Ion Set is not too bad, 700 for the DTXplorer is a hefty pack but if your a budding drummer its not too bad.