I don't think either of the racials are particularly noticeable at level 90 raiding. Yes there's technically a "most optimal" racial, but they all have their place. For example, while taurens do have more hit points (but keep in mind it's base hit points, so it doesn't make stam worth more or anything) level 90 raiders/tanks have so many hit points that it's not noticeable. Yes the Orc Racial is more AP on a cooldown and it's technically an improvement, but it's not THAT much more damage.
I'm undead with my warrior for a couple of reasons: 1) back in TBC when I was leveling, cannibalize was the only way I COULD have leveled a warrior, lol. Way too much downtime/bandage usage without it, and it's surprisingly nice while doing dailies. 2) I originally rolled my warrior to PvP, and well... Will of the Forsaken is THE PvP talent, imo. 3) They look badass. I'm kinda fat in real life, I don't need to be a fat cow thing in my fantasy world!
As far as touch of the grave is concerned: it's nice, but it's not huge. Here's a WoL report: http://www.worldoflogs.com/reports/rt-gtafxoucxugzka2b/details/20/?s=16&e=358
On Tortos I do a lot of AOE, so it's a lot less of a % of my damage, but it's still a 0.4% damage increase (which frankly is probably about what bloodfury is I would imagine, but I don't have any data to back that up right now). On Magthera in that same long, obviously a single target fight, TotG was 0.7% of my damage. So... there is an actual "hey look I did more damage" aspect, and it is kind of nice to get a small little heal while tanking or doing dailies, but it's really only noticable while doing dailies. It's too small of a heal to have a significant impact while tanking.
In the end I think it's which race you think looks the coolest or that you'd have the most fun with the racial abilities. I like undead a lot, all of my characters are undead except a priest I have that's a belf.
So... quantifiably it is technically noticeable... but it's not much, just like the rest of the racials, lol.