The only problem with techie are real 5vs5 fights. Most current heroes are useful for that, but technies actually only had 2 skills for midfight. Sure, he could put a mine or his ulti barrels in a fight but after all he is an int hero and probably dies as quickly as shadow shaman.
His other two skills is a ward that stuns and the next is a suicide that deals good dmg in early game but may not be that useful in the end (unless he really hits all 5 enemies, afaik its AoE?).
Still I would love to see him in the future, he's great if a game is about tactics. Even with a gem, if you dont play careful you may explode suddenly.
