I bought an A852 and compared it to the A52 and to be honest the A852 has more power. The same exhaust and buggy was used in both engines. Like it was mentioned before some parts are interchangeable, but to be honest I see no reason now to buy another Argus since my experience has been slightly better with the Alpha, not to mention the customer service is outstanding in the USA (Argus has no representation in the USA now).