I have many of the CMP ARFs, from little electric gliders to the 1.40 aerobats. I have not looked at too many of their warbirds, only the Hellcat.

Opinions will vary depending on how recent the design is. Most of the latest ones are very good quality - all laser cut, very well laid fiberglass parts with good paint jobs, and plenty of the right kind of glue (e.g. real epoxy in the stress critical areas). Some assembly design could be better thought out (e.g. canopy mounts, etc.) but nothing outright bad.

Opinions will also vary depending on from whom the ARF was purchased. You need to weed out those neagtive comments that pertain to the SELLER, not the product.