Yeah, he is a big disappointment. His battery drains way too fast which doesnt make him tanky at all (20% at lowest.. LOL). I've tried to use my melee weapon for more damage reduction to get energy back and then keep the energy up but it's simply way too much work for a frame that has next to no utility compared to other Warframes.
His CC is nice but the range is ridiculously low since you need to build for duration. The damage of his 3 is terrible though.
Redline is an extremely uninspired ability (which I don't mind that much) that actually punishes you for using it because holding the battery level above 100% is virtually impossible unless you want to spam your 3 or 1.