Well, considering I coach TOPs I may be partial.
In truth, the TOPs program is really great for preparing girls for competitive gymnastics. It focuses on strength training/conditioning and form, which are both crucial to be successful in JO.
The girls (at our gym) that spend time in the TOPs program and then go on to JO *all* fare better than the girls who come from the advanced rec classes. Several of our TOPs girls have been able to skip L3 and go straight to L4, which would definitely not be possible for girls from Rec.
Now, the way our program is set up is such that the introductory levels of TOPs only go 4hrs/wk, and that is the only class they take. We use it as sort of a "pre-team". We want the girls to work hard and progress, but not burn out. We are talking about very young kids here, all of them are 5-8 with the majority being 5 or 6. I don't know that I would sign my 5yo up for 8hrs/wk in the gym but there are certainly kids that are ready for that at that age.... Just not very many.
So in short.... Big fan of TOPs training, I'm a believer in the program and see many benefits to it. However, it is NOT for everyone and we have girls who quit because it's too hard/strict/boring/intense. They have to be willing to work hard and focus, and not a whole lot of 5-6yos are ready for that.
Good luck!!