I have HQ16 and absolutely love it. You should be able to get a pretty sweet deal on the 16 now that two larger machines have come out.
If you go to www.mqresource.com, in the forums, under MARKETPLACE one of the gals has a pretty sweet deal on an HQ16 set up because she is getting the largest HQ.
These are VERY low maintenance machines. I've had mine for 3 years now, use it DAILY, and have not had it in for service yet.
Good luck with your decision, BUT, if you look at other models, be sure to ask about maintenance on the machines. You'll be quite shocked.