Here are the flaws.
1. The B4 top shaft flats were machined too deep causing the inner slipper plate to rub on the motor plate. I saw associated's claim process, and was put off.. So after some searching, I stumbled across associated's representative on this very forum, Don, who helped out without any hassles, and in 2 weeks I received a new b4 top shaft, which solved the problem.
2. The ball cups are crap, they would pop off, and there was a lot of slop. I ordered RPM ball cups from A main.
however, the RPM ball cups are much longer, so now I need shorter turnbuckles, or I would have to cut the RPM ball cup ends, which do you guys recommend?
3. The drive shafts are way too short, and will pop out at full droop. As a result, I had to limit droop drastically until it affaected handling so badly. I did really badly in the Apr 12th race. Foong suggested I used MST 57mm bones coupled with their CVD pins. MST is a Taiwanese company, and I can get these parts locally, so I will be giving this a try. Foongs car ran really well so this must be working.
I will buy a set today, then update you guys.
after the race, I also found some bearings had seized after sand went in, its only been ran 5 packs, so this shows how bad the china made bearings are.
After a few runs, I also found lots of sand inside the gear cover, I was puzzled as to how was the sand getting in, then it occurred to me it must be coming from behind the motor plate , the gap between the inner slipper plate and the motor plate, so I cut a slab of sponge and stuffed in before I slide the slipper plate in.
Next improvement, the instructions call for two 4-40 allen bolts to hold down the battery. Since the batteries will be removed very often, this will wear out the threads in the plastic battery box. So I used two 4-40 set screws which I bought for my Lazer ZX battery hold downs which uses associated B44 posts. This way, I only remove the nuts. I plan to get 4-40 wing nuts, but find it difficult to get in a metric country.
The ball diffs get gritty very quickly, I stuffed some sponge to cover the thrust bearing, but the sponge fell off after the CVD came off the ball diff cups during the race.
So now.. my plans.
1. Purchase some acer bearings.
2. Get the MST bones and pins.
3. Balance the springs and damping ala fred swain method.
4. Remove all internal limiters from rear shocks, get them to 104mm length.
5. Proceed to kick all modern 2wd butts..
A pic of my Rc10 with my LWB Optima Mid, before I ruined both of them on Apr 12th.
what's with the bubble wrap on the shocks? 
). It's the ultimate period suspension... you will only degrade it.