Over on 4Haelz, Bell talks about the Recruit-A-Friend situation. Since we got to test it out last night AND I have some options of my own, I figured I'd just plop them all down here.
First, like I posted yesterday, RAF gives you 3 times the xp of being partied with someone else, not of solo play. Also, it doesn't stack with rested bonus. From the rested bonus grinding perspective, you're going from 200% xp to 300% xp over the normal amount.
The real boost is when you turn in quests, which I don't believe are affected by resting bonus (correct me if I'm wrong). For example, I turned in a quest normally worth 2.7k xp. With my RAF, I got 8.1 xp. This is where you're going to get the real boost in leveling.
Last night we played our level 31 alts for about 4 hours. We gained 3 levels in that time. It's important to note that when you recruit an alt, like we are, it takes Blizzard a couple of days to convert your trial account to paid. This means Fozec's warrior couldn't trade with other players, use the AH, invite anyone into party (I have to invite him), or use the mailbox last night. lol He got an email today saying his account has been updated, though.
You summon your linked friend via the social window, friend tab, meaning you need to add your buddy or you won't have the option. Also, when they say that you and your friend need to be questing together to get the bonus, that includes turning in quests. I missed my quest bonus once because Fozec was across the street. You need to be within probably 40yds of each other (my guess here, we didn't measure it) for the RAF to kick in.
Bell's argument against RAF is that it robs the new WoW player of going through all of the old content. "When you're leveling at 3x's the speed, you'll just skip sections of it and loose the essence of the game."
I would argue that would happen anytime a new player goes through content with an experienced one. Unless you completely go solo or your buddies are all starting out at the same time, you're going to skip over content. Why? Because experienced players know that certain old world areas are boring/don't have a ton of quests/aren't very well done. For example, had I quested with an experienced Alliance person, they would have never let me run clear to Stonetalon Mtns. to do only 2 quests out there. I spent tons of time trying to figure out where I was supposed to go, when I could have been in Ashenvale actually progressing my character.
For me, feeling lost or otherwise uncertain of what I'm supposed to be doing or where I'm supposed to be going isn't fun. I had never done Alliance leveling, didn't know where the towns were, and found the old-world content extremely lacking in what I consider transition quests, ones that point you towards where you should go next.
RAF means if you want the bonus, you need to be leveling with your friend. It's motivation more for the experienced player to help them out and guide them through content, rather than leave them to ask questions over general or just point them towards Wowhead. For the record, I tried asking for help over general a few times. There just aren't enough people in the various old world areas to make that a valid option anymore.
So if bonus xp is a way to make playing together less painful for the experienced, I say go for it. The benefits far outweigh missing out on, say, Silithus (beyond doing the cooking recipe quest).