Originally Posted by TryHard

Yup, a spool is a locked diff. Basically, it provides masses of on power steering (much more than a diff, and similar to a 1-way), as both wheels are being driven at the same rate, and as such if one wheel loses the traction, the other is still putting power down (unlike a diff, which in that situation would "diff-out" and have the tration-less wheel spinning away the power).
Another upside is that is gives the car 4 wheel braking, and as such makes it easier to drive, especially in close quaters with other cars.
The one downside is that they lack initial turn-in, as the wheels are both spining at the same rate. However this can be compensated for in suspension set-up, like softer front-springs, some pro-dive, lower front roll centre, or even running a light-weight spool (running an old speedtech spool, and the new tamiya back to back, there was a marked improvement in turn in. I've put this down to the 8 odd gram difference in weight... might not sound much, but it deffiently works!)

The alu arms are part of the pro-module setup, they are needed to give the clearance for the shock off the wishbone.
In the LWT set you get:
2 pairs of wishbone (1 front and 1 rear per pair)
2 sets of C-hubs (1 2deg, 1 4deg)
1 pair of steering hubs
1 pair of kingpins (upper joint, and lower piviots)
1 pair of rear hubs (1deg toe)
1 pair of complete front axles (steel bones, 46mm long)
1 pair of complete rear axles (blue alu bones, 46mm long)
8x 950 bearings for axles
Plus loads of shims and spacers, and the ball joints etc
I think thats it

HiH
Ed