Damage report:
The tracks we have tested the car on have given it a good enough punishing to see most weaknesses - a long term report is to follow but there were a couple of things that came up during the review which are worth mentioning.

The differential was fine during its first outing on a low traction dirt track, but as soon as we ran the car on a more traditional UK track with higher levels of traction, the diff complained. The balls are the problem and for a longer life it's best to replace them with some higher quality carbide or ceramic balls.

The rear shock tower broke - but this isn't a big point as it was very much expected when I saw it flying toward me upside down and heading for the concrete curb. Just a shame I didn't have the camera ready!
One of the shock cartridge covers came loose and spit its guts out during a run - something to keep an eye on as it's hard to get these covers tight.

The RB5 took a lot of abuse and proved it's built tough.

I took the car out at my local track for some brief testing between Stu racing the car. I ran the car as Stu had set it for his first race at Tiverton, but moved the shocks all round to the outside on both towers, outside on the front wishbones and inside on the rear. The car had a lot of steering on the higher traction areas of the track and I needed to smooth my (low level) driving out a little - but over the bumps, jumps and looser areas the car felt very nice. The car felt particularly nice coming off the main straight and onto the loose, rutted clay banked corner, which can show up the flaws in many cars - the RB5 took this nicely, coming off the power just as I hit the clay and railing around as much as any car can with that much suspension movement happening.
It wasn't a thorough test session by any means (Thats what Stu Wood has done), but the RB5 felt good and better than I'd expected so I came away thinking setup changes could make the car really good. That is the main thing this car needs right now, quality setups and information to help people get the most from it.

There are a couple of odd things about the RB5. The front shocks rub on the shock tower in the middle hole, and won't even fit on the inside hole without being permenantly clamped to the tower. Ok, using the kit springs and with the ride height adjusters all the way down the shocks can be made to not make contact with the tower - but thats no excuse.
The best option is to space the shocks outward slightly, but that would also involve substituting the plastic nuts for some metal 'nyloc' style ones, since there really wouldn't be enough for the plastic nuts to hold onto with the shocks any further out.

The Hex adaptor wheels might put some hardened racers off the RB5 - but really it shouldn't. Optional axles are already released as a hop-up from Kyosho, to allow the use of Losi / Proline rear wheels.

The rear anti-squat settings aren't mentioned in the manual (Though a space is provided on the included blank setup sheet) but it looks to be around 2 degrees. This isn't really adjustable which seems an odd omission by Kyosho. Theoretically you can raise the front block to give more anti-squat, or raise the rear to give less. In practice the front block has almost no room to be raised and the rear block can't be raised at all as it is touching the motor plate / gear cover. This does look like an area that can be modified in a number of ways to enable adjustments, but I'm sure we'll have more information about that in the long term review. Weight wise the RB5 came in at 1557grams on the scales, ready to go. This can of course vary with equipment used. We used B4 titanium turn buckles which reduced weight slightly, minimum weight in the UK is 1474gram.

The quality of the Ultima RB5 is very high. The car is fully ballraced, including the steering. The screws are excellent, and a definite contrast to its ZX5 brother - making the car even more race-ready from the off and a pleasure, rather than a pain to build.
The manual is good and guides you through a fairly simple build process which for the most part didn't post any problems at all. If you have build and raced one of the other main 2WD buggies, you'll recognise most parts and the build will be a breeze.
There is not much of a negative nature to say about the RB5.

RB5 pays great homage to the original Ultima, and is certainly capable enough to carry the name forward to more success - whether it will or not is down to the end user, and of course Kyosho themselves giving the car proper support.

The RB5 needs team drivers and setup help and information to make the most of it. Some other manufacturers cars almost seem to hit the ground running because team drivers everywhere have already tested and refined the base setup which you can simply stick on and race at a decent level. The RB5 isn't quite like that, at least not yet.

With drivers like Stu taking on the car, it will have a good chance to succeed - thats something I'm sure of.