When I turned this tv on I was amazed by the sound quality from those little speakers. They easily rival some cheap htib's for quality and can get extremely loud. For normal watching I haven't turned them past 30/100 yet. Even though the 71's speakers were side mounted and supposedly better I'd put the 750 ahead of them.
That said, these won't even come close to approaching a real dedicated sound system. They lack the fullness of sound and occasionally can get a bit tinny. But they are hands down the best integrated LCD speakers I've heard.