I've had an Excelleron 90 for years and it is very stable and a lot of fun to just fly around, practice new manuevers, etc. I have a YS 140FZ in mine, I added about 3/32 to the trailing edge to increase the incidence and added tip plates similar to a passport. It's very easily mixed for knifeedge and verticals. Added a block to the gear plate to increase the gear length for the 140 prop.
I don't believe they are available in the US anymore and maybe not manufactured. Its too bad. I feel this is a much better plane for aerobatics than the Venuses and other plane in this category. It will do a credible job of P11.
I don't remember what I paid for mine 6 years ago but it was probably about 150. If one were available today, I expect it would be under 300. Brett, are they still available in Australia?

John