@flanker978
In joining this site, you've essentially joined a community of ski nerds, it's kind of like joining a sports-car enthusiast club: most people politely admire each other's boats, but everyone has lots of opinions (and knowledge) on tiny stuff that makes a huge difference to them, but maybe not to you.
So to answer your original question, kinda yes, as long as you don't buy a big wakeboarding boat, you're going to be in a good spot.
Will you notice differences between several good ski boats? yes.
Will they make a huge difference to your skiing and improvement? you can convince yourself they will (most of us have), but most likely they will not.
Back to the minutae:
- yes, the Prostar 205 went from a pretty good ski boat (95 and earlier) to a hybrid wake/ski boat in 96 and later.
- yes, Malibu Responses are good boats. Even the ones before 98. But yes, the ones from 98 on are a bit nicer for slalom, even at intermediate speeds. I'll also point out, given that you've got kids, that if you find a Malibu with a "wedge", it allows you to stop and switch your boat from 'skiing' mode to 'wakeboarding' mode, which your kids may care about as they get older (depending on how young they are and how long you want to keep your boat).
- there are lots of other great inboard ski boats, too. If you see some good deals in your neighbourhood, feel free to post them, but of course realize that it may be difficult to sort through our nerdy and passionate micro-opinions. We may end up discouraging you from buying a perfectly acceptable boat. On the other hand, we'll at least keep you from buying a terrible wakeboard boat.
Good luck!