The X-star is one bad boy and very hard to beat when it comes to space and wakeboarding. That being said it is by no means a slalom boat if that is remotely important to you. I have a 07 X2. It's been a great family boat with plenty of storage and room for 6 passengers. 8 adults can be a tight squeeze if you're out for the entire day but are great ballast for surfing. It wakeboards and surfs very well. It's OK for slalom but is by no means a Pro Star.
If you have the supporting infrastructure for the X-Star (cash, tow vehicle, lift, room to store etc.) and don't care about slalom I'd do the X-Star. If you need something a little smaller I'd do a 214, an X2 or a 214v. If you're concerned about interior size the X1 is going to be the smallest of the lot. Still larger than you have now but noticeably smaller than all the other options.