I was in this debate with myself as well last year. Ended up doing Nitros due to budget and the fact that I rarely off road the truck.
I did the Dobs Nitro set up, 1.5 inch lift (due to fear of KDSS complications on my particular truck), all comfort specs/weights. I found the .5 inch rear springs don't really need the spacers. They seem to lift GXs .75-1 inch on their own. I ended up taking them out as I had quite a frontward rake. Used the AllDogs kit to install later on and the truck is level now.
I find the ride to be very comparable to stock in sport but with less boatiness. It is still soft and not jarring. It absorbs big bumps beautifully. Small road undulations can still transfer, but I feel like that's just the nature of solid rear axle vehicles. I've experimented with different tire pressures to help with the smaller stuff that doesn't seem to be enough to compress the rear springs, and settled on 30 and it is quite comfy. Tire place set my tires at 44. I have no complaints after lowering tire pressures and would install it again. It feels great on washboard roads, speed bumps, big expansion joints, etc. The stock suspension would have a lot of secondary movements and weaving and bobbing and sometimes hit the bump stops. This feels a lot more planted, still absorbant. You really notice it most over potholes, expansion joints, etc. It's just boom one and done, absorbs the impact, and the vehicle body just floats over it all.
I had a chance to feel out an Ironman FCP set up on an LX470, and an Eibach on a GX470. FCP felt the stiffest. Eibach and my Dobs set up felt very similar.