Originally Posted by el capitan
More practical: If you want to ride offroad only take the SX and save considerable money if buying used.
Sorry but I don't agree. The SX gearbox is not only limited to 4 gears, it also has a much closer ratio which really sucks balls for anything but the MX track. If you want to do both low and high speed riding you will have to take apart the engine to at least add EXC 5th and 6th gears to get a decent gear spread, and even then the SX first and second are going to be too long if you are riding technical stuff and you are not a pro that can go fast everywhere.
The SX also doesn't have electric start, and it's expensive to add, as you will also need a different charging system.
Unless you are willing to do lots of mods including the engine internals, I would definitely stick with the EXC.