No worries mate... I think the United versions look great in their alt modes (better and increased number of paint apps), but they're both pretty much the same in bot mode IMO.
As I already have the RTS ones and I display my figures in bot mode anyway, I don't think I'll bother getting the United versions - but for those that don't already have the RTS ones (or live in fear that Wave 1 has/will bypass Oz), United's the way to go.