I have always wanted a bigger tank, regardless of the tank I've currently got. Right now I've got a 300DD but would love to have something with a footprint of 8' x 3'... probably right around 400 gal or so. Anything bigger than that would really push me way up the exponential cost curve and require a lot more space and resources than I would want. The good and bad news is that it would be VERY challenging to get anything that big into my basement. So it means I keep the 300DD which isn't a bad situation.
Bottom line: bigger is better, but only to a point.
Bottom line: bigger is better, but only to a point.