Here's my 2 cents.

I've been working on a new team of 4, boosting with my 80 pally.
I'm loving the new extended XP range, works wonders in instances.
However, I've noticed that the team doesn't get the triple XP when they are far away from my main.
However, when I'm using a full group like that the XP gained from each kill is identical.

So, if you're bringing up 4 lowbies with one high level guy and boosting in instances it seems as though it's no quicker, except for 1-8, with or without RaF.