I did my CFII/MEI add on. It was worth the money IMO. A seneca around here was 330 an hour wet, seminoles 250ish, no real good MEI's available to knock it out. So i decided to go to CRG in Jan of last year when it was snowing here. I enjoyed it. But you will see that the CFI's tend to appear burned out, or just not as enthusiastic as the local FBO i worked at. But 10-12 hour days and foreign students will do that to you.
If you went through a local FBO or mom and pop flight school you could get away with 40-45 K total, but nowhere near 100 hours multi unless you can find a Seminole/Duchess with reasonable block pricing. With that in mind, ATP is not bad. Much better than spending 3 times that on a Embry Riddle or UND flight school. However, be wary of the "extra costs" not listed in the big listed price you see on the website. If you cannot complete it within the designated hours its 400+ per hour for extra training. :/ However they are good at getting you to standards by the time you take your checkride. For me CFII/MEI add on, we basically flew the checkrides 3-4 times each, used the FTD did some oral test prep and it was a breeze. But I had already had 400 hours of dual, so the teaching part was not a problem for me. Just getting used to the Seminole which I had never flown and ATP's SOP's.
Also check rides were 400-500 each (cash only) and you need a place to stay. unless the offer housing for fast track programs.
I was told they only offer CFI jobs to those who complete the fast track programs. However with the lower rate of attrition due to the new 1500 hour rule I think they "guarantee" a job offer, but who knows when that actually comes.
The fact that they offer cheaper housing for CFI's is cool, but the way they pay is weird but will get you ready for the airlines haha. 1300 or so a month guarantee, plus something like 10$ a flight hour. Extra bonus's when students pass writtens and checkrides on time and on first try.
But its true, when they call you you spend an unknown (normally less than two months) at the call center in Jacksonville FL, until a school has an opening that you want to move to.
If regionals are a target for you, they offer the free regional jet standards course after some dual given (300 hours?). I dont know how much weight it hlds, but if you can pass a course like that, the regionals may favor you over some other CFI since you likely would be able to do better in the sim checks.
but im at 1500 and 100 ME and regionals are calling me. So chances are you wont really need the hundreds upon hundreds of multi time to get hired at a regional, nor will the regional jet standards help at all. But if you are like me and shooting for Compass or one of the "better" regionals, if there is such a thing, more multi PIC will help get you in the door. But like many have done, you cpould fly cargo at 1200TT or go to Piedmont or Silver at ATP mins and with that airline crew experience, jump ship after 6 months or so and go to a different regional.
But flying corporate or cargo in the future? That multi-engine piston time will help a lot.
Hope this helps!