Trepanator, that's strange.. i've just got my toons to 77 aswell, so i loaded up the 77-83 profile (BRC) and they're leveling just fine..
they litteraly just hit 78, so it must be a random error
They'll be 83 in an hour or so, so i'll post an update on the tol'vir instance.
Tol'vir is running smooth aswell, probably the best dungeon to use, about 2/3 of a lvl pr. run
1-10 i just quested, using RAF it only took like 10 min.
from lvl 10 - 17, 100% afkable and rly smooth.
(atleast for the horde faction, can't say anything for the alliance since i havn't got a single alli toon)
So far i've only had issues with 17-25, mainly because the booster went off.. and the "noobs" then got too far out of range to run to him

that was sorted by manually going into the dungeon, loading it up and hitting start.. (then it ran smooth)
25-37, they had a small issue, a mob was bugged under a hill.. causing them to get into combat and being "stuck" there for a day :'(
running them into the dungeon as i did with the 17-25, sorted out the issue.
From 37 to 83 (as far as i know atm.) it's 100% afkable, ASLONG as you followed Botanists advice, aka. have enough gold for stuff or the profile will stop..
it's by far easiest to just put 900g on each toon, they'll make some gold off the dungeons aswell (2-300g).
Minor issues with Blackrock caverns, sometimes it WILL get stuck in the wall inside.