Construction is 85% complete.
Overall progress so far:
On the turret I replaced the antenna mounts with a couple of brass items I had knocking around in the spares box. You don't have to replace them if you don't want to (or don't have the spares or don't want to buy brass replacements) as the kit antenna mounts are quite acceptable. I only used these because the top ends where the actual antenna's are attched are already drilled out.
Building the moveable suspension

There's flash on the components as can be seen in the above pic.
Mostly the suspension goes together all OK following the instructions, right up until you get to this stage:

As you can see it's another one of the 'do not glue' steps, and not using any glue at all doesn't work.
This is where you have to glue on the cover plate that brings all the components together. You have to use as little glue as possible on the central "I" part, with the small hole at the top and the pin at the bottom. The plate (on the right in the pic) absolutely will not stay in place here without glue. I considered just gluing the whole assembly together, but wanted to see if they would actually move. And they do. But they're not very strong; it's only the plastic pins on that cover plate and the arm across the top of the bogie (these have tiny connections - and are in two parts) that's holding everything together. It looks like the instructions are just missing the single 'glue' arrow.
I would suggest this build order to build the bogies as stress free as possible.
1. Glue top retaining bar to left/right side bogie and let the glue set. The attachments are seperate pieces in halves; one side is attached to the bar, the other side is a seperate part, and they're handed
2. Glue top retaining bar to "other" side of the bogie and let it set.
3. Check movement: the two main bogie parts should swing free.
4. Insert the rear plate (part B8 in the instructions pic) to B9
4.1 - whilst doing this you'll have to jiggle the springs into place on assembly B9 as they should remain unglued - if you glue them or any stray glue gets on them, the suspension won't move
5. Glue the retaining plate in place (part A30) and set aside to dry.
6. Test for movement.
If you don't set the parts aside to dry, or haven't used the right amount of glue, they'll fall apart.
Moving on you get a choice of sprocket wheels:
After doing some research, the 'rarest' is the sprocket with the step in the drive ring; this was deleted fairly quickly to ease production. I built the 'inbetween' sprocket.
Rear tray/hull plate.
The instructions would have you build the rear tray onto the rear hull plate in stages - which is what I did at first. And had nothing but trouble.
The vertical and horizontal plate of the rear tray are fixed together at the three hinge attachment points, which is accurate, but creates a miniscule and weak joint. Attaching the vertical rear tray piece to the hull first (as in the instructions) makes attaching the horizontal plate exceptionally difficult, as to get the best joint the glue should go on from underneath.
In the pic you can see a couple of the glue splatters that I managed to get by trying to build the tray on the rear hull plate in this way

some sanding and Surfacer 500 took care of these.
I would strongly suggest that you build the whole tray assembly off the vehicle and attach it when it's done. I ended up removing the vertical part of the tray from the rear hull plate and did just this. The PE hinges on either end don't have any markings on them to determine where they should be glued together to get the correct length so that both ends meet up with their attachment points on the tray. Some careful measurement is required.
Tow cable
You get the obligatory piece of string and a couple of plastic eyes to make up the tow cable.
The plastic eyes are moulded completely solid, and the instructions just show the string being butted up against the moulded flat end of towing eye and glued (they don't even mention superglue or drilling out the towing eyes with an Xmm drill bit as they have done in other sections of the instructions), so IMHO this is never going to work.
You can drill out the end of the towing eye. The part is so small that I could't reason that a hole small enough to fit in the towing eye but big enough to fit the piece of string supplied could be made, and it doesn't. The max size hole that the towing eye will take is about 0.5mm. The string is far bigger than that and won't fit in that size hole. This whole thing should probably be replaced by something better...
The lower hull is a flat pack assembly and goes together pretty well. However there's nothing to support the hull sides apart from the attachment points along the edge of the hull floor - Tamiya (etc) would have probably supplied a brace in the form of an engine compartment firewall (etc) for this. RFM don't and you'll need a square to make sure that the hull is... well, square, as it's easy to have the side pieces at an angle. Gluing in the rear plate first doesn't help either, as the glue point on the plate is on a slight angle, and you'll need both lower hull sides in place to get that angle right or you risk not having the lower hull sides meet up with the rear plate.
The upper/lower hull all goes together pretty well after that, but I would strongly suggest that you leave off part "E5" until you've joined the upper and lower hull. "E5" is the row of bolts that goes across the front of the hull between the main superstructure and the transmission cover. Try and fit the hull together with this part attached and you'll have a really bad time.
The turret and gun assembly also seems to be too heavy for it to sit correctly in the turret race.
The pics don't show this very well, but with the turret race in and the turret fitted, there's some distinct slop that allows the turret to sit at an angle. Naturally it falls forward because of the gun, but if you apply even the gentlest of pressure to the rear of the turret, it'll tilt backwards. From what I can see I think it should probably sit somewhere in between. I think that this is due to the two tiny clips that hold the turret in place.
They don't seem up to the job at all, and if you turn the model over with the turret in place, it'll fall out.
I'm leaving the wheels on the sprues until I've primed them black and done a first coat of dark OD. You can see the inside faces of most of the wheels, especially the idlers, when they're together, so this is purely for my convenience and not a fault of the kit.
Usually, at the end of every build I do, and when it's painted and completely finished, I ask myself one question to gauge the quality of the kit, and that question is: would I buy and build another one?
I already know the answer to this.