So here is my experience with my 2017 2150, used now for a year traveled over 9,000 miles.
Pros:
Great floorplan.
Sofa is comfortable, layout nice for 2 people.
Tanks adequate.
Bathroom large and great.
Storage good.
Easy access to bathroom/Refer.
Tight unit, no drafts.
Tows great with weight distrubion hitch.
GD Customer Service better than most.
Cons:
Lippert frame and axles/shackles/springs.
Schwintek (Lippert) Slide mechanism.
Published tongue weight (on mine was 413lbs) Thats empty. With batteries, propane, loaded trailer with "stuff" tongue weight was 770lbs.
Slide has the Refer in it. Makes it heavy.
2 independent slide motors that need to be kept "IN SYNC". This means you need to fully extend and retract every time you open/close the slide or it will get out of adjustment.
No bedroom access when slide in.
As a side note, I have RVed for more than 30 years, and NEVER had as many problems with a slide as I have with this unit. It may be a Schwintek(Lippert) component problem or could be a GD design issue. I've had 2 motors replaced and the full slide assembly (both sides) replaced. Schwintek says because of the slide weight & depth a roller should have been designed in by GD. GD says not needed, I'm not a desige engineer so I don't know.
Good Luck in your decision
2017 Grand Design Imagine 2150RB
2016 Chevy 2500HD LT 6.6L DMAX 4WD
Equalizer 4 Point WDH