Been with FSI a year. After 15 years in the airlines having to deadhead between 800 to 7000 miles to get to the jet it's a nice change of pace being 3 miles form work, home every night, paycheck on time and for the correct amount every time, and free from constant threat of furlough. Pay could be higher but I am certainly living comfortably, and within my means.
As aca Terry mentioned, I have yet to meet someone in any of the centers I have been in that is genuinely unhappy. As with any job in aviation some days you are the dog, some days you're the hydrant. Difference for me here vs. the airlines is that since I've been here most days I'm the dog.
If you still view the cockpit as the end all be all of aviation jobs you won't be happy here. If you dreaded every hour of CFI time you did you won't be happy here.
I'm on my second company paid type rating in less than a year. While it's not a flying job, you will always be 293 and 297 current. Depending on which center/program you are in, there is opportunity for contract work which can help you stay current in the aircraft, and put a few extra bucks in your pocket.
Like everything else it is what you make of it. For me it's not a bad place to hide out for a few years until/IF the industry unfarks itself.