I've had my 1685 for 2 years now, had 2 trips to Florida with it 11,000kms each time, plus lots of local camping trips, very comfortable in the cold weather (4 seasons package, dual pane windows etc.)
Other than the******tires they put on it I have had nothing go wrong with it, nothing has fallen off. I camp solo now so the smaller size suits me very well.
I did a tour of the factory and was impressed by the construction methods they use.
You could check on the Lance Owners forum and do a bit of reading, some people have had some issues with some models, but a lot more people are very happy with theirs.