RE: <<<WHICH IS THE BEST TRAINER>>>
I don't think this is a meaningful question. Any trainer can do the job. There are too many other variables for it to make much difference. A student pilot needs:
1. A trainer that's responsive enough, stable enough, and durable. It should be covered with one of the genuine iron-on films.
2. An engine that provides enough power, is very easy to start and adjust, and is totally reliable.
3. The setup of any airplane makes as much difference as the physical airframe does. Getting the fuel system right, landing gear tracking right, and control surfaces operating freely and precisely matter as much as which trainer you buy. These setup qualities are dependent on who is giving expert assistance regardless of which trainer is selected. Get the best trainer and the 4th best setup helper and it won't fly as well as the 4th best trainer set up by a true expert.
4. Any trainer is going to be different before the student pilot is through with it. A trainer is a "beater" and is going to take a beating. After a couple of "rough landings" the quality of the repairs can make more difference in the flight qualities than the original selection of trainer did.