to be honest, 'speed change' without any further info isn't much use anyway. We're quite on top of the server logs these days so tend to know when we'be got general performance issues. There are always exceptions of course - an ad network at one point was causing trouble and complaints helped identify that. For the moment though, I think that unless there's something unusual and precise, bear with it until the new server is online. It will be public because it will take the site down!