I agree with you Tim on most points except for the importance of wind drift in longer range applications. For me, it's a no brainer to range, come up clicks, then pull the trigger. But judging wind speed is much more difficult than judging distance.
I might miss the distance by a yard or two with my rangefinder, but it's entirely possible I could very well be off 5mph in guessing wind speed or even in wind angle. Heck, even if you have a Kestrel, there's no guarantee that the wind is consistent from the point you shoot to the target.
I may actually be making your point for you since I won't shoot at game long range if there is more than a 5-7mph wind because of the increased variablilty, but still that being said, its so much easier for me to compensate for bullet drop rather than wind drift.
At the distances most people are willing to shoot, I will still contend that the ultramags offer no advantage over traditional magnums, though. For example, using a 7mm Rem Mag versus the 7mm ultramag and 140gr BT's, the standard magnum only drops 2.5" more at 400 and 5" more at 500 than the ultramag. And uses 25 grains less powder. And has a much longer barrel life. Why spend all the extra money in powder, brass, and barrels if you aren't going to take advantage of the cartridge (long range applications)? And if you are going to shoot long range, the heavier, higher BC bullet will shine in KE and wind drift.