In all fairness, the incredible slow speed of the site is a thing for almost a year now (or longer).
And I can imagine it being very off putting if you're curious in Nebula technology and can't even browse the site to read about it.
And I have a gut feeling that it has nothing to do with speed or hosting, but it's a simple DNS misconfiguration on the server on which the site runs. Every request to the site (be it forum, static front page, download page, whatever) just takes 10 seconds to respond. After that the speed is kinda OK. A server that responds with a delay but seems to be otherwise fast is almost always a reverse-DNS problem. Turn reverse-lookups off on the server and / or properly configure the DNS server the server uses and I hope it will help a lot.
Even if you plan on rolling out the new site in like 3 days, checking up on this might fix the current site and people would like 3 days of faster browsing .