I think the stock nsx shifter is pretty good, there's really no good reason to mess with it. I do like trying different shifters though, and find that good shifters/feel can really change and affect driving enjoyment. (btw for the 993, the cae shifter is the best hands down - if you don't mind how it looks). The reason for a sequential shifter (not talking about a real 30K sequential transmission) in any car (there are sequential shifters available for many cable shifted trans cars) is mainly so you don't do a 'money shift' (ie shift from 5 down to 2), and shift a little faster. I also have/had too many manual cars and get confused with the shift pattern - I'm serious it can really be a problem. The sequential shifter obviously makes it different enough that makes it less of a problem. It's also a novelty item that I wanted to try. I don't think many cars have this shifter, it is no longer made, and I suspect looking at prior adds on prime, only a few of these have traded hands multiple times. This one hadn't been used much I suspect as no one had converted it for LHD and the prior owner never installed it. I like shifters that have short action but are closer to the steering wheel.
I'll have to decide if I really like it or not after spending more time with it. It is kind of cool, but you loose the satisfaction or the feel of the gears engaging. It works fine for the street. It is short throw and a little stiff, especially shifting up from 2-3 and 4-5. It is also a little loud. The small lever is the reverse lock out, so that you have to pull it to be able to shift into reverse - essentially you can't go into reverse unless you use two hands.
I've rambled a bit, in the end, motivation to try something different but no really good reason...
I've been lucky enough to have a few different cars, I think I enjoyed the gated older school shifting in the Ferrari 328 the most (once it was warmed up!).