Tech Armor in ME3?

Sentinel is one of my favorite classes, so I've played a ton of them. I always play on Insanity, too, so my experiences should be universally applicable.

You certainly don't have to evolve Tech Armor, but I always do. Between skill evolutions and a light weapons loadout, you can keep your power recharge very low, regardless of Tech Armor.

I generally carry a single weapon, often an Assault Rifle. (Avenger to start. Mattock from Grissom thru Coup. Lancer immediately after the Coup via the goofy ass Clone-Shep mission.) The specifics aren't important, as long as you keep the weight low/cooldown bonus high.

I've even picked Fortification as my bonus power more than once and still been able to have good cooldowns and deploy a powers-based offense.

You're going to be using squaddies to setup and/or chain combos, regardless of class. Sentinels are fun in just how good they are at chaining all the different types of combos, and being tough as hell while doing it.

My advice is to definitely max your Tech Armor. I like to go:
4b (durability, since I don't purge my armor)
5a (power damage, duh)
6a (power recharge, again for obvious reasons)

EDIT: The second post in this thread will be of interest. It specifically quantifies what I've described, showing that Tech Armor (even when paired with a second defensive power) doesn't gimp cooldowns.

bsn.boards.net/thread/1856/effect-single-sentinel-walking-kronner

Tech Armor is worth taking for a power-focused Sentinel, but you do not have to put points into it right away. Tech Armor is good for the damage protection. Max/evolve your powers first, then you can start putting points into Tech Armor.

This thread contains the recharge speed formula, but basically if your weapon weight is 200%, Tech Armor's max cooldown penalty will add only about 0.5 seconds of recharge time, which is hardly noticeable. You should still be able to combo your own Overload with that.

I have played a power-focused Sentinel before that used both Tech Armor and Fortification at max damage protection (so max cooldown penalties on both), and that added about only 1 second cooldown on my powers. I could no longer combo my own Overload but I did not really care. I was using Javik and Liara most of the time, so they were doing most of the priming with Singularity/Pull anyway.

Warp plus throw while you are a tank is pretty damn powerful.