Certainly seems to be a decent idea, I've experienced the power of the older stealth squads and as you said they work well for an alternative to the comparitivly weaker pathfinder squads. But only question is that an average of 2 marker lights for 210 or 152 if not efficient worth the points?
Thats all i got.
I would challenge this with the reason why I took Target locks on the other 2 Stealth suits, around 70 points. In the unit I pose that makes it only 82 points for an average of 2 Markerlight hits
Who needs Markerlights when you're going to simply erase any vehicle you shoot at unless it's a Land Raider or a Monolith?
Less flippantly, I like it; you don't need many Markerlights when you have Coordinated Firepower - even 3 or 4 is getting towards excessive unless you have a lot of units Gone to Ground or snap-shooting.
Buffmander still exists, but you're much better off putting him in a squad that's going to fire after you shoot Markerlights; while he's nice as a tank character in front of Drones, giving potentially every unit in your entire army Twin-Linked, Ignores Cover, Tank Hunter and Monster Hunter on top of whatever Markerlight benefits you got (and probably a huge stack of them, since you dump every Markerlight in your army on your Coordinated Firepower target) is too good to pass up.
A guess a better example than the buff commander would be a Mark'O with Drones. For around 20 points more you are nearly guaranteed double the hits and could be considered as survivable as Stealth with their range keeping them out of trouble. This unit for me was born out of neccessity and I think that says alot about Tau, we have lots of loopholes to jump through to get certain benefits. Farsight Enclaves removes the buff commander as an option. I play Tau currently using 2 formations, neither have a drone unit or Commander so had to find Markerlights somewhere