It constantly runs slow for me, and I am on broadband.
The ads kill it. They are so slow I can see each one loading or hung up in my lower progress bar. If I am typing a new post. The text field will display in the center of the page for 3 seconds, then after some ad finishes it's job, the text field will move back up towards the top of the page. I constantly have to wait for it. No matter the page, just when you think the page is loaded, there always seems to be one more ad left that jostles things around a little.
Add the fact that the meat of this board is consistently 2/3rds down the page or below the fold, and the UX is click, wait, load, wait, finish loading, scroll, get to meat. Finish meat, and repeat.
It's why I always preferred thread view because I could easily pick out where the meat might be by thread title, # of responses, and whom was responding.