it's horses for courses, I have a 999S and have ridden 4 999 bis and have to say that I like the grip the ohlins seam to fined, the way the power is made on the 999S is more at the top end, you will change up at 8'000 on a 999 but the 999S makes most power at 10'000. it's great all you need is 3rd and 4rd when you want to get a move on.I love it. and it's worth more when you come to sell it and more desirable,
but the 999 is a little bit more civilised at 3'000 and round town,
but out side of a city I think the S has it quite clearly won.
but try both and make up your own. but beware the feeling of a tuned engine in full song which is fitted to the S can be addictive.