rich-joy, it can happen to any site but Mudcat is particularly prone to periods of extreme slowness.

A reasonable indicator is to try other sites and see how they download for you. If they are running slowly too, the odds are the problem lies with you or your ISP. If it's only Mudcat, the chances are it is Mudcat or perhaps (and less likely) something on the route to Mudcat. There is a command line program on Windows called tracert that can show how long each hop is taking. Another thing you can try is Mudcat is to try the backdoor (207.103.108.99/threads.cfm) sometimes you will find the frontdoor working slowly but the backdoor is quick or visa versa.

When Mudcat and everything else is running well, you should find broadband makes a difference. Perhaps not so much for the usual 1 day listing of threads or opening shorter threads but I do when the text gets longer, eg on dialup, I used to find threads getting very slow as 100 posts approached - that's no problem now, although with the really long threads - sat > 200, I do open a page at a time.