^^^So, you both bring up some good points, and this is what I'm having an issue with. FWIW, we are nowhere near buying (more financial than anything else), but are still shopping around so that we can nail down exactly what we want, and how much it will cost, for when we ARE ready to buy.
So, right now, it's 'kind of' between two different types of trailers. The smaller, 7'-wide trailers, like the Apex Nano 208BHS:
http://www.coachmenrv.com/travel-trailers/apex-nano/208BHS/4011, and larger, 8'-wide trailers, like the Avenger ATI 26BB:
https://www.generalrv.com/product-prime-time-rv/avenger-ati-travel-trailer/26bbSO, we have been doing pop-up camping for the last few years. We LOVE our pop-up, and one of the features I like most about it is that we can fit it in just about any site we care to. If we want that small river-front or lake-front site, it's not a problem. We also do a fair bit of battery camping - that is sites that don't have power. A pop-up is perfect for this, as really the only thing you need to run are lights, and occasionally the furnace if its really cold at night. A battery and a solar panel are plenty enough to do a week of battery camping. At this point, I am leaning towards the smaller camper, for a number of reasons:
A) It is smaller, and therefore easier to fit into tight camping sites. I'm pretty sure if I could fit my pop up (which is 20' long when unfolded, and 7'-wide), I could pretty much fit the little Apex Nano.
B) The Apex Nano seems well setup for battery camping. The small interior space would lend well to keeping it warm when we need to kick on the furnace. The higher amperage furnace fan is what will drain a battery overnight, and the larger the space you're heating, the more the fan will run. Interior volume of the Apex Nano would be similar to my popup, but with a higher R-value, as heat wouldn't be escaping through tent-walls. For the warmer days, it has a lot of window area, compared to the volume of the trailer, and the two ceiling vents have 12v fans installed to help circulate air when you can't have AC running (because your site doesn't have power)
C) I think there would be a marked difference between pulling a 7'-wide, lower profile trailer, and an 8'-wide, tall monstrosity like the Avenger. I'm not only talking about frontal area, but also side profile, which is one of the leading contributors to sway. I'd like to pull a trailer across the continent if possible, and a large trailer would just make it harder. Harder on fuel, and harder on the driver, as I would need to work harder to keep the trailer under control, see around it, etc. If we went with the Avenger, I would be tempted to keep our pop-up, and use it for the longer trips, relegating the Avenger to half-day drives around Winnipeg at the most, whereas with the Apex, I could sell the pop-up, and take the Apex on longer drives.
D) Is interior space really all that important? Currently when we camp, we spend most of our time outside. We cook outside (under the awning, so I can cook when its raining), eat outside (unless it's raining, but even then - we have a dining tent), and generally just hang out outside. If it's really miserable, (cold/rainy), the wife and kids will retreat inside the camper with the furnace on and watch movies/play games, but I generally like to sit outside and watch the rain from the shelter of the awning. That being said, last year we didn't have a single day of rain while we were camping. It rained at night sometimes, but never during the day. So, the trailer is really only there to store our clothes and food, provide sleeping accomodations, and act as somewhere to shelter if its really miserable out. BONUS POINTS: The APEX Nano has a partial exterior kitchen, facilitating my outside cooking mission.
E) Again, related to space: My stepson turns 18 in June. My wife has come out and said that she's not going to force him to come camping with us. If he wants to come, he can come, but he doesn't have to anymore. Knowing his personality, I think he will opt to stay home, especially as he gets older and starts to enjoy a little more independence. This means that I foresee most of our camping trips just being my wife, daughter, and I. Do we really need a behemoth trailer if its only the three of us? If my daughter decides she wants to bring a friend camping with her for the weekend, well, we'll have the extra bunk. And if my stepson is with us, the dinette still turns into a bunk.
F) Build Quality. The Apex Nano is $8 000 more expensive than the Avenger. I feel like it is built to a higher quality. The construction is the more expensive sandwich construction. It has a one-piece end-cap with an integrated windshield. I feel like the interior materials are of a higher quality than the Avenger, meaning the parts you don't see (like the roof) are likely better quality as well.
G) The one detriment is that the Apex Nano is more expensive than a trailer like the Avenger. BUT, in point C, I argued that if buying the Apex Nano, I wouldn't have to keep my pop-up trailer. I think with the improvements and repairs that I've made to it, I could easily get $5000 from my pop-up, which would go a LONG way towards closing the price gap between the two trailers.