The Baja is cool, it’s a fun ride, but requires wayyyyyyy too much maintenance for my liking. I sold my g4x pretty happily when I needed some quick cash. And my life is better for it 
If you already have the g4x, don’t bother with the s2. Clearance sucks with the 8 inch wheels and makes any sort of off-roading pretty much impossible without doing damage, and the s2 on the 10 inch wheels sucks for torque, which you need for off road.
That puts the S2 in a solely on-road category in which case your money would be better spent on a kaly or lacroix in my opinion.
Edit: i’ve spent a good amount of time on the g4x, s2, trampa mtb, kaly 2 and prototipo… not a great deal of time on the nazare but enough to get a feel for it.
By far the Kaly is the best of the bunch for on-road. Super responsive, fast, the deck is to die for… the only thing that lets it down is the remote. But that’s an easy fix.