Nav IMO is a waste of money. You can update GIAA every few weeks on your I pad, load and build trips. Nav in the dash will get outdated and cost more than a new I pad. I have no experience with KDSS but hear it works great on the road. I prefer my trucks to work better off road. Its just something else that isn't really needed and is harder to put sliders on the truck and how well it work with an aftermarket suspension system?
I plan on a GX for my next truck and yes a neused GX will run me 40K+, people ask if I'd really take a 40K truck on the trail? Heck yeah that's what it is designed for! I wished I could get a stripped down version but they are not available. If I could find the right new one, say base model at 50K I would consider it hard.