We have the same trailer you are buying with the Trail-air----fine Lippert Product....smooth ride. We left the dog's water bowl full whenever we travel (closest 8 hours away) and it never spills. You are going to have a lot of electronics inside and a lot of close fitting cabinetry---a smooth ride is important.
Lippert 6 point Leveling System---very handy, makes quick work of set up but expensive. I'd get it again....
If you like ease of set-up it is the way to level and stabilize very easily but don't expect NO movement inside-you can notice other folks moving around. Also, it will take a SLIGHTLY unlevel spot and make corrections but we have had times where we had to put blocks under the jacks to get it to level without reading "excessive stroke" or whatever the message is when the rams have to extend too far to level. It is a long trailer so even if it the spot looks level, the gradual slope barely noticeable to a a smaller trailer on the same pad, may cause greater (further reaching) strokes on your trailer's jack system. You are covering a lot more real estate!
Good luck and Enjoy!