Super Swamper TSL vs. TSL/SX

[SupraLux]

Howdy, this is one for the Swamper fans out there... I need a new set of tyres for the MU and have an opportunity to buy some 36" TSL/SX's

I've driven 31" TSLs but not the SX variant on the road, and was quite suprised that they were reasonably quiet and handled pretty ok compared to extreme trekkers.

Are the SX's worse, being that they are supposed to be more 'offroady'? What are they like for wear long term? Are they noisy (relative to non SX)? Anything else I should consider?

Cheers in advance

Steve