BARCC, the answer is that a 50cc will fly the CAP-X crazily powered and will fly the 27% Extra VERY nicely.
You should do some research on these planes (there are several threads on the CAP-X and CA Models 27% Extra). You'll get a lot more info there than aqsking on an EF Yak thread.
Here's JohnVH's latest RCU review of the CAP-X with DA-50 [link=http://www.rcuniverse.com/magazine/article_display.cfm?article_id=500]click here[/link]
You can also go to planes plus
http://www.planesplus.com/Products/Aerobatic/extra.htm and watch the 27% Extra video with a DA50...