Well, I finally succumbed to temptation and ordered the superbike bar setup for my K12R from boxer-design. Have had it on the bike now for about a week and have been adjusting to the new ergos and handling of the bike. Overall, the more upright position-streetfighter style makes the bike a hoot to ride now in the twisties and definitely more comfortable making your way through slower city traffic. Coming off the stock bars, turn-ins feel sharper (don't ask me why, I'm hopeless with the technical side of steering physics but I'm sure someone here can shed some light) and for lack of a better explanation, I'm riding the curves (on a road taken many times before) faster and holding better/more accurate lines with less effort. Steering is generally now more sensitive to rider input. At crawl speeds however, there's a more noticeable resistance which I suspect is caused by the steering dampener. I'm going to try to a few different tire pressure combinations next to see if it helps any.
What was expected with the more upright riding position was windblast when making the high speed runs on the freeways. Seem to be more susceptible to left/right gusts which was initially a little unnerving. Because the bars are now closer, there's less room to 'tuck-in' nicely behind the screen. Yes, folks, the sports screen does work just in case you're wondering, as the difference is quite obvious. This is probably the biggest compromise in return for more comfort and sharper handling. 'Which is better' is now pretty subjective to the individual rider.
Material quality and finishing is top-notch but personally I would have preferred a less-shiny or perhaps a plain brushed or powdered finish to the base clamp,.. not that it's bad, just my preference. Installation was left to the professionals as I wasn't sure I was ready to take on the job on my own. All in all, a fantastic setup that brings significant changes. Looks brilliant, a little pricey but probably worth it (seeing as there are no other alternatives) if you're looking for an adjustment or improvement in that direction.