I have built several and have several more to build. I am in the process of converting a 40 size Sukoi (in the Brettling scheme) to electric, have built the Subaru (a very nice kit), a 90 size Edge 540 (also a nice kit), a small electric extra 300 (no issues, good paint and clear canopy), a giant scale Pitts (superb construction, laser cut parts with a very good design, good covering, poor paint, flys great), another electric extra only slightly larger (very nice kit with some paint issues but good fiberglass and plastic), a very nice power sail plane (actually has good hardware), some 40 size caps (Brettling design, beautifull little planes, but I have to repaint the cowls and do some covering work to make then near perfect in apperance), a 40 size Mustang (good kit), a 71" Gee Bee that is just stunning, once you get past the gear issues, and some Four Star type planes with good construction and covering. In general, I find, in these models, good design, laser cut parts with good construction usually, amazingly good covering jobs (better than most of us could do), and sometimes, paint that matches and good canopies, also i must say that they are usually light weight as well, however, instructions are usually poor to nonexsitant, hardware is usually fit for the trash can, fiberglass that often leaves a lot to be desired, canopies with bubbles and wrinkles that are even cloudy sometimes, often week landing gear, paint that needs redone, and sometime parts that are installed incorrectly. Bottom line, you need, building experiance, covering experiance, painting experiance, knowledge of control systems and structural requierments, and a cashe of spar parts or a hobbby shop close by, to succeed with many of these models. Having said all that, many can become beautifull models in the hands of the right builder. I have included some shots of some of these planes.