I'm running the eBay kit and it wasn't 100% bolt on had the have the hub centre hole O.D. machined down as it was too big for a std Escort size wheel centre hole.
Also if your concenred about keeping your cars weigh down then it also best to avoid them or the other brand simply because of the components used.
I was quite suprised at their weight. It was around and extra 6-7kgs or something from memory over my old setup.
For the money I paid for the kit, I shouldnt really complain

Im yet to test on the track.
Rhys