Layout has as much to do with it as actual length. I had a 28' and a friend had a 24' at that time. His felt larger because of the floorplan. 6 ppl fit comfortabley in his where mine was crampt with 4. His shower was larger but I had much more storage. Mine was a bunkhouse with front queen bed while his was just one big open room.
A slide in trailer makes sense for 2 or more people - more room to pass each other in the narrow corridor btw dinette and kitchen counter. For a single person a 24-26ft trailer without slide is plenty (i.e. 21-23ft actual box length). Especially for a male (my apologies if I assumed wrongly). You will find it huge after your current 19-footer. Two people is a different matter, more closet space needed for partner, etc... Mostly, it's about narrow shape of a typical TT - that's why a slide for a 2 or more people. TT can be very long, but they are all narrow, 8ft usually. And you don't want it longer than necessary either.