Such great points. My parents got burned buying a second home for all of us kids to use on the weekend when we grew up. Then, we all moved away and today no one uses it, including them.
So, when we got our TT, we got it for us two, not our kids and grandkids. I figure they can always pitch a tent if they want to come with us.
So, we looked for small, but where DH with mobility/health issues can turn around, stand up, and use comfortably. We went with the smallest new one I could afford.
Small size works for us - the TT is for sleeping in, getting dressed in, cooking/eating if bad weather, and using the facilities. We are generally out and about during the day and stay outside until time to turn in.
We also made the choice of no slides. Just level it, drop the stabilizer jacks, light the hot water tank, switch the fridge to electric if available, put out the outside chairs, and we are done. The 14ft fits anywhere.
For us as new campers, going new was an easy decision and it works for us. No issues from former owners not maintaining to our satisfaction.
Some choices made it easy for us -We don't camp in the winter because cold weather is hard for DH with COPD to breathe in, so no need for covered tanks, for instance. We just winterize it and park it in the side yard and I use it as an office in the winter.
Look at what you will carry - The 14ft floorplan we went with had more open space than most 16ft floorplans. That is important when carrying an oxygen concentrator. There is a shelf headboard which holds a bpap machine.
While we would have liked a step in bathtub type shower, ours which has a shower floorpan is easier for DH to step into, although he only uses it when we disperse camp and uses the regular bathhouses when available as they are easier on him. So, the shower can become a storage area on those trips and I pack accordingly. I carry less stuff or use a tent as a storage unit when we are going to use the shower.
2016 Shasta Oasis 18BH, 2015 Ram1/2 ton Hemi