The reality is that virtually nobody is in a position to compare good modular training providers, because if you've found a good provider, you tend to stay there.
Negativity is an awful thing, but I think it's your best bet here - I think you need to go looking for the criticism, and avoid anywhere that's attracted a lot of it.
After that, realistically, it's location and price. Most FTOs are well run, have enthusiastic and dedicated instructors who'd nonetheless rather be flying an Airbus, use similar average-condition aeroplanes, and will have a fair number of satisfied licence holders who will attest to the quality of their training.