Linda, I have had a 590 for almost 10 years and 440 prototype before that. Both were bombproof. The 590 is a heavy boat for it's size, with a very deep hull. It's fast, but goes through anything. We get a lot of short, steep seas here and I wouldn't trade my boat for anything... Well, except maybe a 640 or 733!
I'm not too familiar with the 540, but I recall that it is a fairly basic boat. I don't think it has inboard fuel tank etc., and is a somewhat lighter boat.
Assuming the hull is a similar shape as mine, I suspect you'll be very happy!