In reply to tradlad:
A sacrificial wall rope costs like £40 and if it's a decent ten mil then will actually take a surprising amount of punishment.
Personally I find being comfortable with falling makes a massive, massive difference to my climbing but of course YMMV. Many of those who don't 'get' the point of falling practice are either naturally unfazed by climbing right at their limit with massive whipper potential, or mostly climb well inside their limit and seldom fall off.
My experience of it though is that you do need to do it a lot and regularly for it to be very effective, though if you redpoint a lot then you end up clocking up lead falls while working routes so it doesn't take dedicated practice.