Yes, the only advantage of a trainer is that their stability is much greater. But most of them lack the control authority to recover from really difficult situations, like a stall 3 feet above the ground when coming in for a landing too slow. Even if you got a 90 engine on a 40 size trainer it won't recover in time due to the small elevator authority.

Now, with a profile things are a lot different. Although they are not as stable as a trainer, they are much more "controllable", can almost stop in the air (in the horizontal position....) , land on your feet, takeoff after 5 feet runs and so on. They may seem a little sensitive at first, but nothing that a dual rate, some expo (computer radios are very cheap and popular nowadays, basic 4 channel non-computer radios are for the real stingy ones) and a nice instructor helping won't solve. As you progress, you go increasing the throws, like leaning out an engine after each run during break-in, and after a while you got a wild 3D machine on your hands.

Of course, if what you want to do is fly more "scale-like", then the "conventional" types are more recommended. But for someone with 3D in mind, there's no point in expending extra money buying a plane that won't do what you want. Save that for buying a replacemet when you crash (with a trainer or not, you will crash somewhere along the path, no point in hiding the truth). Of course the semi-scale planes like Funtana and such are not really recommended for begginers, because not only they lack the positive stability, they lack the slow speed handling also... So they are better as second planes.

Just my 2 cents though....