I haven't leveled a full team of 5 ever, but I have done the following all without RAF:

- Leveled my first core "4" (paladin, priest, mage, shaman) assisted by my 80 warlock "main"
- Leveled my druid boosted by the paladin, ported around by the mage/lock
- Leveled my rogue boosted by the paladin, ported around by the mage/lock
- Currently leveling 3 more shaman, boosted by the paladin (but not ported as on same accounts as mage/lock)

Honestly, if you aren't in a race and enjoy some PvP its not bad. Even without a booster if you can pvp some level's not a chore if you aren't in a huge rush. In WG weekend, I didn't use my paladin for my 3 shaman and just BG'd all weekend. I think I went from 20 to 28 and these weren't marathon sessions.

Just my two coppers.