I originally towed my 17โ Casita with a 1997 80 Series LX. Foot to the floor to move its 3500lbs.
Got the 2007 100 series LX and it was much nicer, but still heavy pedal for any incline.
Got a 2013 200 Series LX and it was like having a diesel when pulling the Casita.
Then got the Oliver II, felt like it was the 100 series and the Casita again.
I love the 200 for what it can do when not hooked up and it handles the mountains fine, just have to be happy to be in 4th at 3000 rpm much of that time.
So, at 5000lbs you can use the 100 series. But you will be constrained.
Now the Elite 1 and the 200 series, my perfect combination. ๐