Which RV for boondocking

I think your choices are both viable, so it really falls on your personal likes/dislikes.
we like our diesel pusher and would look for one slightly bigger (more slide outs) if we went full time. but we recently got a pickup for our toad because we want to take a golf cart with us. I see you have a "toy" you'd like to take, too.
I don't know how long trailers last compared to motorhomes, but I'd guess a lot depends on your regular maintenance.

Probably, you can take a toy hauler places you cannot or should not take a motorhome. Some boondocking places have pretty rough access roads sometimes.

Finally, the only critical thing for me in a trailer is that I can use it with or without the slides out.

The toyhauler provides more flexibility. You'll have the Razor to play in and your tow vehicle to run errands in. The garage of the toyhauler provides a space that can be converted to whatever you need when the Razor is unloaded. Workshop, entertainment center, guest bedroom, additional living room, office....etc.

If something on the MH drivetrain goes bad then your house may end up at the repair shop and you'll be in a motel. If your tow vehicle breaks you can send it to the shop and still have your home.

consider fresh, black and grey water tank capacity.

Though I loved our quad, but going to the same area gets really boring on a quad. I learned all the leaves and rocks up on the Rim here in AZ. Also a quad has different licensing and use laws in every state. We eventually got rid of the quad after about 5 years because it just got boring (we do not race it we site see).

IMO I would go the DP and Jeep. Jeep has licensing and use laws similar in all states. If you are not in AZ you can drive the jeep on the highways to get to new spots to site see.

If you are going to spend a lot of time sitting (not moving) in the desert, you are better off not buying a diesel pusher. The advantage of a DP is moving, not staying in the same place. If you will be moving every week or two, buy a MH, gas or diesel.

Just an FYI, our trailer could be dragged to more places than our class A can go. The weight of the class A (22K+ lbs.) makes driving in sand, mud, and soft clay much more difficult (and risky). There is no way our jeep can pull our bus out of a quagmire but the F250 we had could pull the trailer out of anything, from the back or the winch in front, which ever worked better.
We also are more timid driving the A on truly horrible roads that we would drag our tt on - we didn't have to listen to all the noises in the tt; in the class A, it sounds like a major earthquake (which I guess it is).

If you want to be more remote, a tow behind is easier. If you aren't wandering very far off the road, a class A works.

2chiefsRus wrote:
consider fresh, black and grey water tank capacity.

X2...DP. If you are going to stay in the same place for a month+ at a time then the TH.

I love my MH.

In my opinion, something having the largest tanks you can find, plenty of room for solar panels on the roof, and space for a good size battery bank (450 Ah minimum).

I have 115 gallons fresh, 65 gray, 45 black. Three weeks is not difficult, four weeks if I conserve. 650 watts of solar provide all my electrical needs.

The rest is pure opinion and what fits YOUR lifestyle.

I prefer my Jeep and bicycles. I don't care for those quad things but obviously a lot of folks feel differently - hardly seems right to suggest that what I like is the "right" approach.

JFNM wrote:
In my opinion, something having the largest tanks you can find, plenty of room for solar panels on the roof, and space for a good size battery bank (450 Ah minimum).

I have 115 gallons fresh, 65 gray, 45 black. Three weeks is not difficult, four weeks if I conserve. 650 watts of solar provide all my electrical needs.

The rest is pure opinion and what fits YOUR lifestyle.

I prefer my Jeep and bicycles. I don't care for those quad things but obviously a lot of folks feel differently - hardly seems right to suggest that what I like is the "right" approach.

This was us exactly as we had a Newmar DP, too.... big tanks and solar... but only two weeks on the tanks with the two of us. We were easily able to travel on good gravel roads without boulder hopping.

We also had lots of enjoyment with our Jeep.