I think a solid trailer is easier to deal with by a long stretch, be it the vastly superior FG trailer or a sticky.
That said... pop ups can have more floor space for a family than a 13 ft scamp
which can sleep two kids but getting ready would be pretty tight for two adults and two children. May have a greater availability on the used market, weight
being equal they typically have less wind area so you might get better fuel economy.
However FG trailer will hold it's value much better, and will probably sell much easier than pop up. FG camper offers greater possibilities to customize and make it your own or add value. You also have to consider if you want a toilet and shower, not typical in a pop up, available in FG 13 ft camper.
In use I think you will find a solid wall camper with it's ability to park and use with minimal set up, and ease of pack and go to be more user friendly. You arrive at a park 9:00 pm on a Friday do you want to set up or just park?
Pets would be easier to deal with in a solid camper than a canvas walled one I would think.