That ballistics chart is great. It compares only the best 6.5mm bullets (Laupa) fired out of long barrels.
For a better take on what it'll actually do from YOUR gun, head over to
Brassfetcher.
120gr. Norma FMJ from 14.5" Barrel: 2405 feet per second
120gr. Sierra Matchking from 16" Alexander Arms rifle: 2393 feet per second
(Before anyone claims bias, note that that test was sponsored in full by 6.5Grendel.com, Sierra, and Alexander Arms.)
Use a 20-24" barrel and you'll get better velocity. In other words, with proper bullet type (soft point, JHP, or other hunting round) it'll do fine on deer. In terms of bullet weight and initial velocity, it's a little better than 7.62x39mm. It will hold its velocity better than the Russian round, though, especially if you use the Lapua long range match rounds (though I don't think these are expanding rounds and may not be suitable for hunting).
It's not superior (for hunting) to .308, .30-06, .243, or .270. None of those cartridges will fit into an M16 magazine, however, which is what the 6.5 was designed for. 6.5 was designed to give better range and more power to something the size of an M4 carbine, and it does that well enough.
Ballistic coefficient never killed anything, though, and there are excellent, highly aerodynamic bullets with superior ballistic coefficients available for nearly every caliber rifle if you're going to be handloading anyway. Not really a concern with deer hunting, though, since your shots *most likely* aren't going to be all that long. (That depends on the terrain and your marksmanship, of course.)
Less than 200 meters? The deer's good as dead.