1900lbs empty is too much - your not even at your passenger weight - all the other packed stuff - kids bikes - diapers - water - food - etc.I've been reading the other threads... yeah, the Quicksilver trailers look awesome, but with 2 kids we'd like something a bit bigger. I might've considered their XLP if the tongue weight wasn't 250lbs dry. That chassis should last decades (WAY longer than the canvas).
I've seen some subaru's towing teardrops online (check the forester & various trailer forums) that are around 2000 lbs... plus they've got more drag and get pushed around by the wind. Personally I wouldn't want to do that, but think the pop-up could work.
If I buy a new trailer, I'll probably keep it longer than our Outback...
I towed my 21ft 8.5ft wide racing sailboat lots with many different vehicles over the years from our 2001 Legacy GT 2.5 5spd MT - to our 93 Land Cruiser - multiple friends cars - and the 2010 Limited 2.5 with CVT. Empty with a set of sails - basic Coast Guard gear flairs - horn - 2hp 28lb honda outboard and lifejackets the boat weighed 1350lbs the trailer was another 450lbs. So just shy of 1800lbs I towed it with the 2.5 cvt a fair amount. #1 The cooling capacity has always been the final stopping point with the 2.5 not power the 2010 and newer models are far better than the older generation subarus regarding cooling capacity however - you will 100% run out of cooling ability long before you run short on power even with the 2.5.
Running solo no kids - no extra gear just the boat in tow - the 2.5 ranged from 16mpg with a head wind at 60-65mph - to 21mpg with no head wind at 60-65mph flat towing!
Do not plan on doing any sort of long climbing 5+ miles etc in outside temps exceeding 85 degrees with 1900+lbs behind the car. That gets progressively less regarding climbing as the temps get higher even mild rolling hills in 100 degree weather with you pushing 1900+ could find your self at the end of the cooling capacity depending on head winds and your windage etc.
Which is why when I sold the boat which I and the wife raced together since 1998 - my camping rig plans were 1200lbs or less for the camping trailer paired with the Subaru.
If your planning on using the RV lots and over a wide range of seasons and having it for a very long time - I would avoid all the RV "Junk" with plywood floors and press board interiors. The Livinglite 13footer is a fantastic rig! That would be at the top of my list if I were doing off season camping and wanted a hard sided rig with standing head room and bunks for the kids.
If it were just the wife and I a Campinn Tear drop would be hands down my first choice granted no standing head room or kitchen inside etc.
So for now the family RV is a 4x6 utility/tent trailer which is just a tent - with two queen sized beds and empty weight is 890lbs. We put boats or other stuff on the top of the trailer which has a hard top built to haul a ATV - we don't have a ATV. Just a couple of small sailboats. The 2.5 with CVT does about 25-26mpg at 65mph on the flats and gets down into the 21mpg in the hills towing that set up. We can also go ANYWHERE with that trailer given even fully loaded to the max the 2.5 will be capable of hauling over the Rockies in the Summer months etc.
Only reason I would want hard sided RV is for off season camping which case if the Wife and I get into that after the kids are gone - then maybe we get a pickup with a nice hard sided cabover camper and perhaps tow a boat of some type we can do some mini cruising on like San Juan Islands etc.
I think you can get a basic 13ft bunk bed + queen livinglite in the 1500lbs empty range if you keep the fancy options limited and don't fill the water tank. Which is far far better than 1900lbs before you even get started with the kids crap and the wifes pile of must take stuff.