I would love to hear some views on this one, personally i think trigger time in any gun is good practice BUT a airsoft pistol has little or no recoil, so if you bought a look alike to your "CARRY" piece, and you trained extensively, would this mess you up?
It depends on the person, of course, and what types of training one requires and expects to be able to accomplish with an Airsoft pistol. For example, if one is still striving to achieve decent combat accuracy, needs a lot of practice in order to do so, and owns a decently accurate Airsoft pistol (preferably of similar weight to the real thing, or at least with some heft), then shooting it extensively can only help, in my opinion. It probably wouldn't hurt anybody else to do so, either, but if one is reasonably proficient already (in slow fire) and can get range time on a fairly consistent basis, then I'd prefer to practice with .22 LR or larger, obviously; that said, I shoot Airsoft whenever I feel like it and it doesn't seem to hurt me any. The key is to practice at the range enough to maintain familiarity with recoil and the other effects of shooting firearms.
I also use an Airsoft pistol to practice rapid sight picture acquisition and getting off the first shot as quickly as possible. Actually shooting it at a paper target helps verify the accuracy of my aim at speed, and it's great to be able to do this at home any time I want and at extremely low cost. The result seems to translate to shooting the real pistol in this regard as well as rapid fire, which I only train for at the range, of course--gotta have recoil and muzzle blast & flash for that, but being able to reacquire the sight picture quickly certainly helps.
With regard to trigger control, I prefer to dry-fire the real pistol with snap caps and a laser attached to judge how I'm doing--I use an extremely cheap Airsoft laser sight (took it off a pathetically low-quality Airsoft pistol I bought on clearance for a couple of bucks
) for this purpose since I currently don't own a combat-capable laser sight. Using an Airsoft pistol is OK for this purpose, especially if one needs a lot of practice in this area, but for achieving a fair degree of refinement, using the real pistol and a laser is probably the most effective training method; the only thing it won't help with is flinching, which one will have to diagnose and correct at the range using live ammo, of course (using a laser would help in this case, too).