It's a older thread, but here's the little I've learned.
Training wth laser grips or guide rods can do a lot to help you with trigger control/grip/stqance but it'll require a fair bit of focus to get that from it. This is because they are either always on, or have a seperate activation method that is outside of the trigger mechanism. In the case of always on types it'll allow you to select a point and help you see how alterations in stance/grip/trigger control etc effect the ability to hold on that specific point. since there is no change with trigger activation/release you can only surmise/estimate where the "shot" would have landed. It also partly depends on where your focus is, and what your going to train you focus to be. Front sight vs laser on target? Gotta choose, or possibly start training bad habits.
I picked up a NLT training pistol. My particular version has the dual laser, in red/green. The red is activated by trigger press, then the green flashes when the trigger breaks. This allows the benefit fo tracking the red through trigger movement but also a momentary flash of the brighter green laser to identify whee the shot actually landed. Even with a good front sight focus I can easily spot the green laser out to 20-30feet indoors (that's as far as I've been able to train) Unfortunately the green does not work with any available trainer targets based on my research. There is a way to swap it out so that red is the momentary on, but I haven't done this yet. Partly is because I don't feel the need. I can ID the green flash well enough, and I'm not really looking to drop another bunch of money on the comercially available laser targets (yet). The 2 lasers colors and momentary activation permits better training I think, especially with draw and fire drills as you can visualize trigger activation vs where the shot would fall.
I have no interest in the NLT system, but it seems the most refined out there at this point. Also only available in a glock 17ish style frame at this point, FWIW.