Yes it is different.
The SX2 is an evolution of the SX. The S1 designation means it uses GRP composite where the higher spec kit uses carbon fibre. The S1 chassis appears to be favoured by team drivers anyway so no bad thing.
A negative with the SX2 is that Schumacher, presumably to save costs, substituted many of the alloy parts for plastic ones, hence the need for option parts.
