With the advent of very fast, high performance microlights and LSA types I think it is time to amend the Standard Overhead Join to reflect modern day performances.
Anyone who has seen a Quik or a Pegasus CT climb skyward would realise that crossing the upwind numbers is not as safe as it once was when performance was measured by PA28 types and light Cessna's.
As the LSA category gets wider and wider acceptance there will be more and more very high performance aircraft getting up beyond circuit height at or about the upwind numbers.
It's time to re-think the procedure and I for one prefer to aim half or at least one third down the runway for my crossing point as our local circuit height is 500' and the Quiks are at that height in seconds.
It is true that a large number of Pilots make the mistake of joining crosswind somewhere along the extended centre line and even if they have joined overhead it is still poor airmanship in this phase and potentially very dangerous.