Just coming back on 2b's question regarding the Skyteam Chrome Sports exhaust, as I fitted this within a couple of months of having my Ace, and can report that it is a definite improvement all round.
It was fitted in conjunction of having the larger jet on the carb, and the overall effect was a considerable improvement in performance, and whilst it has a deeper & more "gruntier" sound, it's certainly not loud enough to be offensive, and don't anticipate any problems being stopped by the rossers!
Pricewise, Skyteam UK were selling these out at £160.00, which all things considered, I did not think was unreasonable, and mine has kept it's chrome fine, although it has constant wiping of GT85 / Scottoiler 365 to keep the corrosion at bay.
I think that they look far better than the std. black exhaust, and would definitely recommend!