For all intended purposes, they would give a very similar reaction. If you know that you room has quite a bit of ambient light that you can't control (or isn't easily controllable), and the television will be facing it, it is definitely a consideration. Respectively, no unit should ever really be in direct sunlight, as you'd be very hard-pressed to find a panel that would work in that kind of environment (CRT, LCD, DLP, Plasma, etc).
That said, once you turn the television on, often times the ambient "glare" goes away once your eyes watch the picture. You might want to go to a store where there is a lot of lighting, and turn off the panel. Turn it back on. If the ambient lighting goes away and that's acceptable to you, it still might be a solution that works for you.
Just a few thoughts. But there isn't much of a difference between the two panels as far as glare is concerned.
Thanks for considering a Samsung!
Looking to purchase a 46" Samsung LCD TV. We have lots of ambient light in our room, and are concerned about screen glare. Is there a difference in the screen, from a glare perspective, between the LN46A750 and LN46A650? Are they the same material w/ same coating?