For the record, I don't find this tiresome at all, this thread has been one of my primary sources of entertainment for the last two weeks or however long its been going. I'm actually going to miss this thread when we finally conclude it. So thank you Ditto for putting up such excellent arguments for Voldemort. I might disagree with them, but for the most part they are very quality points.

Now back to my direct comparison between the two.
You are probably right that I overestimated the casting time for V's spells. I'll cut it down to one second, since much faster than that gets A) Hard to calculate, and B) means he's pronouncing things so fast they'd be gibberish. I'll assume a half-second for effects like apperation and flight, much faster than that and V'd be apperating before he actually had realized he needed to apperate. I'm also going to assume that V needs a wand to perform any magic, including apperation, since I can't remember anybody in the books doing so without a wand, and wizards seem generally crippled without a wand. Loss of a wand will not cause V to fall from the sky if he's flying, that's an ongoing effect that clearly perists when he is wandless (see: book 7), but he will be unable to begin flight wandless. Fair?

However I do not agree that I'm over estimating Sauron's ground speed. He's bigger than a human, meaning he's got longer legs, has massive physical strength and probably does not tire as people do. He's also going to be very agile, since as you agree he dominates in melee. All this boils down to somebody who, while probably not capable of winning an Olympic dash, can nevertheless move very quickly. If anything I'm shortchanging him in terms of melee reach, since he's bigger than a human and will be able to use correspondingly longer weaponry, but ten feet is an easy number to work with, so I'm sticking with it. O

Now, outside of a hundred feet, Voldemort is going to be completely unable to hit. In fact, this is probably true unless he's within fifty feet, since lots of spells miss at that range, and Sauron is going to be far better at dodging than your average indoor and out of shape wizard. He's also bigger, which is a strike against him, but I'd say his superior dodging skill will probably overcome this. Nevertheless, it is fair to say that Voldemort will want to open up from long range, since its fairly obvious to everybody involved that getting hit will reduce him to a greasy black stain, so let's assume he starts a hundred feet from Sauron, with both combatants fully aware of the other's position (apperating makes a poping noise, so its use for ambush is impaired).

Sauron will most likely begin to charge, and cover let's say ~35 feet when V gets his first spell off. Sauron's still outside of easy hitting range, and is a moving target, so V probably misses. V casts his next spell, which S either dodges or magically deflects. Now S is within 30 feet of V, V will be dead before he can get another full length spell off. He either has to apperate or fly, since flight is apparently highly difficult (he's the only one to do it), let's assume he goes for the easiest thing and apperates 50 feet directly behind S. Since S is moving foward at a goodly clip, and is within 17 feet of V when he disapperates, let's assume that S manages to halt his forward momentum and turn around at V's former spot, by the time V get's his next spell off. The two are now 67 feet apart, so the spell is a miss.
Sauron charges again, getting to within 30 feet (I'm rounding off the two feet here) before V gets his next spell off. S deflects said spell. Again, V will be dead before he can get his next spell off. Since apperation did not gain the needed advantage, V takes to the air, S comes to a halt on the spot where V took off from. Now that V is flying, I feel that its safe to assume his accuracy is somewhat reduced, to say 40 feet. That is, V has to be within 40 feet of S to have a hope of hitting. Assume that he does this from straight overhead to maximize his height advantage. S dispells V's flight spell (its an ongoing effect remember?) V is now falling from 40 feet up. V's reaction time is half a second (given his age, that's being generous), and years of magical training enable him to get his next flight spell off after only falling 30 feet (I'm assuming that he flies here, since most people when falling don't think about appearing someplace else, they think about stopping the fall). Unfortunately, he is now only ten feet away from S, who jumps up and cleaves him in half. End of battle.

Conclusion: I feel that my givens were very generous to Voldemort, I gave him very fast spell times and the ability to escape whenever possible. I even gave him the benifit of the doubt when falling (if he'd not managed to pull out of the fall, it would have killed or disable him. Again, end of fight). The only things I gave Sauron are his documented melee skill and speed, and his known ability to deflect/block spells, as well as a reasonably fast ground speed. All of this was not enough however, and V still ended up dead.