I'd echo GG's comments. Also, I'd suggest moving the thread to General Discussion rather than GenTech - I think you'd get more responses there.
From my perspective, I've got a walkway camper (Trackabout Safari Extenda), and it's brilliant. Much more room inside than a traditional camper, and the walkway makes getting up in the middle of the night super easy. With a 9mo that doesn't sleep more than an hour at a time, we're up and down A LOT during the night :/.
The downside of course is the longer trailer body, which will eat into your offroadability. For the places we go, it's never proved an issue.
Now - comments on the Johnno's trailer. I've only seen them at camping shows, never out and about. I find their model hierarchy to be confusing. IE, when I last looked, the mid-range camper had a 60L underslung water tank. But I was interested in the next model up that had a lot of better things, but no underslung water tank - it was side-mounted for some reason. But the top-of-the-range model had it back underneath. I'm not sure if this has since been rectified, but for me it was a case of "2 steps forward, 1 back".
Looking at the one you've linked to, a couple of things jump out at me.
1) Internal door to walkway section. I don't like how that sits. Imagine you've spent all day dragging the camper through thick gloopy mud. You pull up at camp and set up. Suddenly, you've got a filthy muddy door inside your camper. I also don't like the separate step that you've got to slide in to the receivers, through the canvas. That's just another thing to deal with.
2) Kitchen bench space - or lack thereof. That would annoy me quickly.
3) Sloping walls on the tent - vastly limit internal space compared to straight walls. You can't put beds/stretchers/etc close up to the walls. Check out the Trackabout site (
www.trackabout.com) to see what I mean, or check my camper thread.
4) Toolbox looks very small in all dimensions. I'd rather have the jerry cans side-mounted on the trailer, and make the toolbox the full width of the trailer. You *WILL* end up filling it completely with "essential stuff" (read, "crap").
5) Spare wheel on drawbar. I'm not a fan. I rather them on the tailgate - it's just wasted space on the drawbar that you could use for other storage. But that's just me.
6) Stone guard is vertical. I prefer the stone guard to be canted forward, to bounce rocks back down. I've heard stories of flat stone guards bouncing rocks straight back up at the rear window of the car.
7) Walkway looks narrow - looks only about 30cm wide. IMHO, that's too narrow. Trackabout started out with a 1' walkway, but it wasn't good. They now do a 2' walkway, which is perfect. Some other brands have a 3' walkway, which (to me) is too much - it's just wasted space.
That pole across the doorway that GG mentions would annoy me.
I do like the floor vent inside the tent - that's a god-send in hot weather. Likewise, the big windows.
Biggest thing for me would be to see one in the flesh, and to see how long it takes to put up/down, and how many poles it involves.
Again - I've not had any real first-hand experience with them, but that's my take based on what I have seen, and the photos of that one.
Good luck!
Matto