One of my previous bikes was an S1000RR and I have ridden a few different V2s and V4s, and now have a 22' V4S on the way.. so maybe I'm biased here. It really comes down to personal opinion and what you're intending to use the bike for. I'd honestly say just stick with the V2.
The S1K is a great! I really can't fault it apart from my opinion that it lacks soul and character compared to the Ducatis. Riding around on a Panigale just feels immensely special, even when going slow. They're exotic and unique and something you can stare at for hours on end, but you really can't say that about the BMW.
I also find that casual to moderately paced street riding on a V2 (or even V4) is so much more enjoyable than on the S1K since the inline 4 engine in the BMW wants to *scream*, so cruising around at low to mid RPMs just feels wrong for it. It's like an old V10 F1 car just going through the pit lane at low RPMs - knowing it wants to scream makes me feel guilty not constantly taking it to redline. Yet on a V2 or V4, I can listen to the engine purr right along at any RPM or throttle input and enjoy it. Meh.. maybe I'm weird.
It also depends on what you're using the bike for, though. As a daily commuter in hot weather, I can see the BMW winning on comfort and heat. If you are dying for more top end power and your primary riding style is setting land speed records on highways, maybe the BMW is for you! Do you spend any time on track?
P.S - Post some pics of your V2
