I just bought an ASP 52 and am VERY impressed!  I read a very good review here http://www.rcmodelreviews.com/asp52_review2.shtml and agree with everything it says.  More power than an OS55 AX at 1/3 the price.  Starts easily, idles to about 3RPM and has tons of power.  Will it last as long?  Probably not but you can just buy another one :-).  If you buy one take note of the bit in the review where he advises about the screws holding in the carb.  When you use Loctite you have LOTS of lube so go easy on the torque otherwise it's REAL easy to strip the thread.