Well, as with all stealth characters...stupidity < easily counterable stealth.
And my point with the 1v1ing is that if someone decides they want your jungle? There's not much you can do about it aside from running away and falling behind. So yeah...it can work incredibly well. But jungle Twitch is really, really banking on it working...and I just can't honestly recommend it for the vast majority of players/teams in the vast majority of situations.