Well, that's one of the things I hear from people when they explain why doubles are better than triples. Until very recently I had a triple on my commuter, which I basically treat like a rented mule. It eventually gets into a state where the shift from the small ring to the middle ring is slow and requires a little extra nudge, but I generally only do that once a day so I let it go.

The thing that I personally don't like about indexed front shifting -- even with a double -- is that it's no where near as good as friction front shifting. Yes, when it's properly tuned indexed front shifting works like a switch and the higher quality groups have enough trim settings to keep the front derailleur off of the chain in any gear I'd use, but friction shifting is perfect, as in I can always put the derailleur exactly where I want it, even if it's been a really long time since I last tuned up the bike.

I don't get the thing about friction on a mountain bike. Admittedly, I haven't done this with a flat bar set up on a mountain bike, but perhaps my absolute favorite thing about the Gevenalle shifters on my CX bike is the way I can throw the chain where I want it with a sweep of the lever. If the lower limit screw is properly adjusted I swing the shifter all the way to one side and the chain goes onto the small ring and without the "whack" of indexed shifters. Now moving to the middle ring could be an issue if you had to do it quickly. I'm not really a mountain biker, so maybe I just am not picturing the critical scenario.