I have few years worth of on-hand experience with optimizing sites (my own) getting anywhere between 500k-1mil page views per week. All that running on lowly $20/m server. Making a site run fast is not rocket science if you know what you are doing.
Like a lot of people mentioning here, I too often find BC load horribly (from whichever country I login). Most of the time its hard to say what the problem is, it could be server side (php running withput opcode cache or mysql without memcache or unoptimized) it could be front-end (no cdn, unresponsive bloated js, non-minified, non-gziped static files). Whatever. There are 100s of ways you can optimize a site.
But one of the worst offenders is the number of DNS queries a browser has to make due to external static file (js, css, images), which would also include social widgets like twitter/g+/facebook that you guys decided to put on every single forum post
as opposed to each thread or each page (which is bad enough). Every single post means how many DNS queries are being made per page client side?
My suggestion would be to remove the social crap (who is going to use it on a forum?) and make everyone's life a little bit easier.