Something you have to consider with server speeds is that you are making connection through a great number of other server systems that DreamHost nor you will have control over. We cannot in all honesty expect a server half way across the world to be as fast as a server under the desk.
With all the servers that DreamHost are putting on line it is bound to happen that one server will be out on the tiles overnight and give a poor service until it has recovered. But that can happen with other companies as well. The DreamHost people seem to be a committed bunch and I feel that a problem with a server is going to be as much of a ‘personal thing’ to them as it would to us, and they always seem keen to sort out any little niggles.
The best thing is to try it and give it a fair trial for a few months. Take reviews with a pinch of salt sometimes just in case there is a personal axe being sharpened. If you do not like it then ask for your money back under the 97 day option and try elsewhere. But if you give them a fair trial I think you will be satisfied with the value for money.