As to what, either the 720P v. 1080P, or the bit-rate (in my example above, the 720P is at ~5.600mb/s, whereas the 1080P is ~12.1Mb/s.
Depends on the equipment; most 'consumer' HD displays, particularly 'flat' LCD based ones, even with the 'best' you're probably right, very hard to note any...