If we were dealing with Russian troops in the same numbers as Syrian/Lebanese forces, if they were attacking us, then yeah, we would take them on. I'd like to think that our training and most definitely our equipment are better than Georgia's. If we're dealing with Russian troops in Russian numbers, where they can overwhelm us easily, no, I wouldn't want that, though if it was already happening, I'm fairly certain we'd take a pretty heavy price, at least in the beginning. After a while we'd be drowning in the enemy.
Unfortunately, stories like Avigdor Kahalani and Zvika Force in the Golan Heights in 1973 are the nadir, not the norm.
The case can also be made that there have been plenty of Soviet "observers" throughout the region, and that IAF soldiers have shot down Soviet MiG's flown by Soviet pilots over the Sinai desert. Not the same as tanks, but still indicative of the skill level of the IDF, at least back then. I'd like to think it hasn't changed that much.