As someone who has very limited playtime, I frequently find myself soloing and TFs are pretty much not an option. My point of view, therefore, is one of a mostly soloist. I enjoy playing through missions and have little interest in PLing unless it is to get past a particularly slow portion of the leveling process. I'm not a completionist by any means. I like having different tracks for my alts to follow to keep me from getting bored playing the same content repeatedly.
I would very much not want to see XP rates reduced. I would be tempted to lobby for an increase, but not more than 1.25-1.5 times current rates. Frankly, however, I think they're fine how they are. I rarely play my 50s and I don't really understand the rush to get there. I have enough alts that I can leave some unplayed to accumulate Patrol XP before playing them and save the Experienced power uses for 30+, which allows me to artificially increase my rate of gains.
Personally I would prefer a smoothing of the leveling curve so things don't slow down so dramatically at certain points.