I loved the Z1 too. Yeah I had a few problems but nothing serious. Water leak and trim kept falling off the counter tops and tables. When I bought my Z1 I bought it as a gift for my wife on her birthday. It was all about the payment at the time and I thought it was the right trailer for us.
The plan was to trade up in 4 - 5 years. So I got to thinking why keep paying on this for 4 - 5 years only to trade it in and start over. So I bit the bullet now. This way we have the trailer we want and it will be paid of quicker then if I had to buy it in 5 years time.
The big reason I went to a sunset trail was because of the construction differences. Fiberglass sides with alum studs and mine has the appollo tech insulation. The Z1 is mostly wood.
The layout was also a little more friendly for us as well.
In the meantime I still think the Z1 is a great trailer.