I have to say, I'm very happy with my T4'17 Al flex kit. There were a few imperfections but when the car hit the track it was fantastic right off the bat. I'll list my complaints but these are not an indication of dissatisfaction in anyway - no car kit is perfect:
- Some of the orange spacers for the upper deck were way off in spec... too thin which if used would place considerable stress on the upper deck and pinch the layshaft bearings. I had the same issue with some spares I bought and had to throw them out.
- The omission of the inner battery stop... easily resolved thankfully.
- The ARS arms are not Graphite and CANNOT be used without reaming.
- Very little adjustment range with the ARS.
- had to shim the rear ARS steering block for up/down play
- They were not kidding about the diff o-ring expanding - I wasn't happy with my initial fluid level and rebuilt the diff before I even ran car. No way that thing was going back in. I used Tamiya anti-wear grease on the gasket and there is zero leakage so far.
- the short steering tie-rod for the servo is too long and can't be adjusted to make the angle between the rod and the servo saver 90 degrees. You have to shorten the rod or cheat with radio settings to get perfect left right travel
- Doesn't include hard front bumper, the light one should be the option.
I think many racers are afraid of the ARS but they shouldn't be. It doesn't do anything drastic and gives you very precise control of the static toe which is a nice quick tuning option. I'm running on carpet and it's wonderful.