Jaba, the 600 kg's is only for factory lsa and lsa experimental. The quotes earlier from elsewhere on a forum by Frank are PROPOSED only and for this rv7 the mtow would be 544 kg.
The ga experimental question comes up frequently. You cannot owner maintain a used GA experimental aircraft, but you can an RAA aircraft regardless of whether it is factory or homebuilt unless it is a factory built and used for hire or reward under which circumstance it mustbe maintained by a minimum of an ra-aus level 2 certificate holder.