I don't know about the current lot. My bike is at least a dozen years old. But it has STI and it is wonderful. The shifting works just fine and of course this means it works fine for several years.
The only downside is weight. They do weigh more than downtube shifters.
I'm sure the bike shop showed you how they work. Way back when I got mine there was one 'problem' but it really only applied to racers. A tap on the small lever moves one chain smaller either front or back. This means it is harder to jump 3 or 4 gears in the back to jump away. Not a concern for non racers. If it is I think the Campi system allowed you to accomplish this in one shift. (I find I can shift pretty quickly with repetitive taps, more than fast enough for anything besides serious racing).