Had my SQ5 since last Sept and more than happy with performance (especially the shocked look from Porsche drivers), and I've only just tried the launch control.... Let's just say I think a little bit of wee came out.... 2 tonne beast of Bodmin.... 
I don't know, I think the SQ5 is quick out of the hole but the initial turbo lag at a stop light isn't really that quick. I think its actually closer in the 6's 0-100km without launch modeI recall that it's listed in the owners manual, apparently the transmission ECU records each attempt, it's pretty brutal. In essence you stick it into D/ S mode, one foot on the brake the other on the gas, lift the revs to something like 3k rpm, and just lift your foot off the brake pedal.
As we all know however this side of serious high performance cars there is very little out there that can keep up from a standing start in just normal D mode, so launch control just does a harder start....
Thats what a good remap removes. It improves normal drive up to the level of the sport mode but without having that harsh sport edge all the time. Sport is then increased to "fcuk, this is mental"initial turbo lag