Although I have my complaints with RB and they are many, I don't have the problem of slow loading pages. Now I did have that problem, oh gee wiz, I'd like to say about a month ago. Each day for a few days service was slow and terrible.
But like I said for me today has been quick and just fine as it has been for the past several weeks. If I were to surmise, I would think that they (RB) are in the process of either upgrading parts of their system and you just happen to be on that slow end for now. I don't know how they are setup to handle traffic but I'd surmise that certain segments of their system would handle certain segments (ISPs) of network traffic and you just happend to be in the area that is beng worked on.
Just my two cents - a FWIW I'm happier over here these days for the bulk of my posting - just sort of keep track of some friends over there - cause they "haven't seen the light yet". LOL
Good night and good luck,
GG