Try running a speed test at http://www.speedtest.net
See if your current internet speed is slower than what you pay for.
I did go in the room and it is a little slow but probably due to all the new size icons although that shouldn't be an issue after first loading as those are cached in your browser.
You can try adjusting the max messages you see under room settings. Change it from 100 to 30 or so and see if you see a difference.
You can also try using the streaming version which only loads new messages as they are posted which uses a lot less bandwidth after first loading the room.Edited: