Hard question to answer, but maybe just some things to consider.....
I know there are many people on this forum who were former pop up owners and went to a teardrop or tiny travel trailer to get away from the hassle of dealing with the canvas. I also have friends with children that camp a lot, were former tent campers, and think their pop up is the greatest thing since sliced bread.
We camped in them a lot when I was a kid. I wasn't really responsible for the set up, but it always seemed to be a big deal. And then if the canvas happens to be wet when you have to put it away, you'll need to open it back up again and dry it out once you get home or you'll have a mildewy mess. I have heard of raising winches failing, of owners having near misses with them closing on their fingers/hands, and other such horror stories. Don't know if those are very isolated/rare incidences, but the way Murphy's Law operates in my life, I would be the one.....
One disadvantage of pop ups is the lack of sound proofing. You will hear every sound your camping neighbors make through those canvas walls and vice versa. If you camp in isolated areas away from the masses this may not be an issue for you. Maybe you are the kind of person who can easily tune that stuff out. I can, but my husband cannot. A teardrop, especially if it is insulated, will definitely be quieter for those private conversations, or.....
Do you want to camp in all seasons, or at least 3 extended seasons, or are you strictly in it for the fair weather? Back in the day when I camped in pop ups they didn't have heat and air conditioning, so I can't speak to how well those systems work in modern day pop ups, but heating or cooling a tiny teardrop, especially if it's insulated, will be a simple matter. The downside to the teardrop in inclement weather is that there is not much room inside to stay out of the weather, but most people deal with that by using pop up canopies with side walls or something similar. (In that regard you're still dealing with canvas (or rip stop nylon) which needs to be set up and broken down.)
For us a pop up wasn't really feasible because one of the primary uses of our trailer will be for traveling which means frequent nightly stops. I knew I didn't want to deal with all that set up/break down mess under those circumstances. And also for bicycling tours, where we'll just want to park, jump on our bikes and go. We needed something we could just open the door and fall into bed after a day on the road, and simply close it back up and get back on the road again in the morning.
I think that pop ups are very well suited to families with kids that want to be able to camp off the ground, not spend a boat load of money on a trailer, and for the most part like to set up camp and stay put for awhile before they have to break it all down again. If you are currently a tent camper a pop up will likely be a huge improvement since you're already dealing with canvas and pop ups have a lot more of the "comforts of home."
As with everything there are many factors involved that only you can determine. What is your planned use (how, where, when do you camp), how many people must you accommodate, what is your budget, do you want to be camping NOW or are you willing to delay that for the time it takes to build your trailer?
The pop up definitely offers advantages when it comes to interior space while still being lightweight and towable by a smaller vehicle. I looked at pop ups at the RV show last year that opened to 20' long, slept 6 or more people, had inside showers, and features that would rival a nice travel trailer. To be honest, if I were more into long term camping where you just drive to the campground, set up and stay put for awhile and then break down and drive home, I would have been very tempted. Some of the offroad models were extremely cool with gear decks to hold your ATV or bikes or whatever. Very nice. Just not right for our intended use.
If you can't decide, perhaps you could try to find a very inexpensive pop up, camp in it for awhile, and if you decide it's not for you tear it apart and use the frame and whatever parts you can salvage to build your teardrop.
Whatever you decide, getting out there is the goal, so good luck and have fun camping!!!
