Long stroke gas piston:The AR platform is available in both a DI(legacy) and Piston(pick one) now.
Steel sub frame:The Forged AL upper/lower of the AR/M16 series has proven plenty durable.
Larger extractor:you gotta pay $2k for a bigger extractor??
Rugged bolt (that won't break ever 10-15k rounds):If you run quality bolts from Colt,BCM,DD they will last that long or longer.
Ability to be converted for left handed use (w/o using aftermarket parts):I admit the Tavor is "better" for lefties out of the box;the AR with the M16A2 left case deflect works,the charging handle is ambi.With aftermarket support more so.
And increased reliability in harsh environments:How so??
The AR/M16 program had some teething problems due to early deployment,kinda like the SA80/L85(still crap) due to politics,wrong propellant,no cleaning kits,poor training.The weapon has undergone some good PIPs and will continue to do so,albeit MUCH too slowly.
Colt for years has tried to upgrade the platform but the military powers do not accept everything.Colt had a piston gun 40 years ago,long before the HK416(me likee) or aftermarket stuff(mid 1980s) like the RHINO system.
If properly maintained the AR/M16 platform is very reliable. If US military would have adopted HK416 type improvements it would even be further refined.
Not trying to dis the Tavor.The ones I handled and shot at SHOT seemed well made and interesting,but bullpups haven't proven to be the "next generation" The Izzys will continue to field large quantities(free US $$$) of M16 based guns for years to come.
FAMAS:
SA80/L85:
FS2000: how much for an even more plastic gun???That lil poop chute ejection "port" has me concerned.Clumsy handling.
AUG:kinda like this one,ahead of its time. The true quick change barrel is most useful.A3 platform better.Could use further PIPs.Still expensive for a poly gun.