Yeah if the sequential shift is anything like the one on the regular smart then I'd stay away from it entirely.
My GF has a regular Smart, and the gear shift is "interesting" to say the least, it takes quite a bit to get used to things like:
Approaching a roundabout in 6th, due to doing about 65-70 mph, braking and downshifting 3 times, as I know that I'll want 3rd gear to go round the roundabout, and then being out of gear for 10-15 seconds while the box works out what to do :shock: it definitely makes for interesting times.
Sometimes even shifting one gear can leave you in neutral for 2-3 seconds, and heaven help you if you shift the wrong way then try to correct it(up 1 then down 2, for instance)