Ok the cons are humdity in the mountains when it get cooler at night with the furnace going the canvas can get damp if you are camping real late in the year condesation drips on you, but only when sleeping in seems
Setting up and taking down in the rain sucks
The best advice I can give you if you have powered site get electric blackets those are the best thing every invented to a tent trailerist
Make sure it has a fridge and not an icebox, and a hot water tank is nice....well to have hot water
When we shopped around we looked at them all and the best we could find was Coleman/Fleetwood built strong good warranty the wood they use is heavy duty no cheesy stuff, and this is the only brand I would buy.
I have the Coleman Bayside it has 2 king beds dinette slide out tip out and a couch we have had it for 7 years and it has been awesome for us could ask for a better tent trailer. The only reason we are replacing it is we do a lot of ramdon camping and quading and it would be nice to have a bathroom rather than the great outdoors and a sponge bath
Here is pics of one the same as ours except it has different colors inside
http://homepage.mac.com/wkharris/PhotoAlbum41.html