High quality airsoft guns can be useful for training. The airsoft club at the Air Force Academy convinced the local Security Forces Squadron to evaluate their use for training. The SFS requested additional funds to buy more and standardize their use...
Simunitions and airsoft each have their pros and cons. Simunitions operate more realistically (especially for rifles), but are more expensive and carry a greater injury potential. Several simuntion rounds tore through my friend's BDUs and lodged in his back (at close range). Airsoft requires much less protective gear. Full face masks and BDUs are the most I have seen in airsoft; whereas Simuntions required vests, full helmet/neck/face protection, and groin protection. The other issue is simunition malfunctions. I have seen 2 simunition rifles malfunction (1 FTF and one double feed) during 3 short scenarios. I have only seen one airsoft gun jam (faulty, low-quality mag was the cause) out of probably over 100,000 BBs fired. Sims cost quite a bit, while airsoft BBs can be had at $12 for 5,000.
Tokyo Mauri, Classic Army, STAR, and G&G make decent airsoft rifles (usually $200-$500). The controls will be similar (although the charging handle allows access to the hop-up instead of its normal function). Gas Blowback pistols usually have identical controls/function to the real steel models. Western Arms, Tokyo Mauri, KSC, KWA, Maruzen, and Marushin are the top manufacturers (Cost: $100-$300).