The SPS and S are very different bikes.
The S is a later model and uses the engine of the earlier SPS (minus the Ti conrods), but other than that is very different.
The SPS has many additional carbon parts and Ohlins front and rear (the early ones didn't have Ohlins front though).
It also was a limited edition run and each SPS is individually numbered with a plaque on the top yoke.
The SPS also came with a pair of race 50mm carbon termis, a paddock stand and a cover.
The SPS is a single seat only, the S was a dual seat only (I think).
That's just a few of the differences.... the other difference is the price, you'll pay a lot more for a SPS than a similarly S.
Tim
