not all arfs are good. when i got into the hobby 25 years ago you usually had to build a kit to have a well built model. back then arfs were almost non-existent. years later when arfs became popular i started buying them and they were not to bad. but nowdays they are very popular and they are mass produced and that is where the problem starts. they are built much you would build a kit but on assembly lines in china, vietnam for companies here in the U.S.....one problem with arfs is the glue they use.. like hot glue guns with a very low grade glue. every arf i buy i re-glue a lot of the structure i can get too ....one in particular is the engine firewall.i've had a few come loose. now i completely re-glue the inside with epoxy. the other problem is the covering on them and the way its applied. when i built kits i would use balsarite on the wood 30 minutes before covering. i applied the covering pulling it tight and ironing it down carefully making sure the glue on the covering is bonding to the wood. most arf manufacturers do not do that. the covering is cut from stencils and then applied to the model and the seams are are sealed. then it is sent thru a heat oven to shrink the covering and adhesive "kicks off" before adhering to the wood. i have two kits that i built and covered many years ago and the covering is still sealed and drum tight. i have had several arfs that the covering had lots of wrinkles because the glue is not bonded to the wood. some it just fell off of them and i had to re-cover them. also some arf manufactures use a unknown covering that does not color match any of the known quality coverings such as monokote, ultracote, oracover and a few others. if you have to do repairs your out of luck. recently i learned that two popular companies that i bought arfs from for years that used quality coverings is no longer using those coverings. they are now using the "unknowns"................sorry to ramble on but just putting my 2 cents in.