15% bc makes me say the msp, because the msp in the pipe and park is still great, its better to have that girth in the BC and bring it to the park, rather than have a smaller underfoot for park and pipe, and go skinner in the BC....if that makes sense?
yea, between those, go with the msp. even though you don't ride a ton of bc, you'll be happy to have the width of the msp when you do find some pow. plus, the msp is still versatile enough to do just fine in the park too.
I have the 170 msp's, and I love them. Rode 165 pocket rockets before, and the msp's are definitely a stiffer ski. I've skied the 175 ARV's, and they are an awesome ski. but if you like soft skis, not sure if they'd be the best bet for you, they're a pretty stiff ski. I ski mainly BC, but the msp's are awesome in the park, and I suck at pipe so I can't really give you an accurate review on that. But all in all the msp's are a sick ski, so I'd definitely recomend them.
A bad day skiing is better than a great day doing anything else