Well recommend is a big word. It's the way that fits my playing style best. I can't do the same thing over and over for too long (except maybe if it's a first time). About the boosting: yeah i usually run with 1 shaman in ramparts & mana tombs, and with 2 in shat halls. Sometimes i just add other toons to the run to get them up as well, but those are more fillers and have no priority. I see that i get about 1k per mob killed all the time, sometimes its 900 and sometimes 1100 xp, 2 shammies (lvl 80s) give less xp. Once they hit lvl 72 i will be running with my geared 80 tank through the instances with the 3 dk's and a dps shaman. The other 2 toons will be accompanied by 3 lvl 80 shammies (since there should be no longer and xp penalty as far as i know when they are within 8 levels). And probably do some less annoying quests.

About /played ... i have no clue. I think i did 55-70 in about 15 hours on a dk. My /played time does not reflect the actual time played, since i'm afk about 80% of the time, if not more.

But regardless of how exactly i do it, boosting in rested time and questing while purple tend to work best for me.

Ualaa has described in other threads how to boost toons to 68 by killing mobs in howling fjord with shamans (with stoneclaw, stoneskin & magma totem), where your 80's are outside the lowbie group, and where you tag the mobs and the 80s totems kill it (considered pets). That should be the fastest way, but it's rather brainkilling.