I've got lots of thoughts on them. Depends on the person really....
TransPac did exactly what I wanted. I went their to get a steady wage for my loans/bills as a single guy. You don't make a lot of money and you work A LOT so it sucks, but they do get you hours. 11 1/2 months I got 920 dual given hours and I was out. If you want a enjoyable CFI experience and not in a rush to move on, I don't think it's a great place to go. If you want hours as soon as possible and don't care about anything else...it's a good place to go.
You'll work 50 hrs a week and in the beginning you teach private which is only 50-60/month....but once you get to instrument you get 100-120+/month. If you have your MEI, your hours will drop pretty significantly because it's LOTS of sims. I didn't get mine and just stayed in instrument until I was done. Any other specific questions shoot them my way!