Rossignol S4 Jib vs Armada Alpha 1

Thanks to everyone who helped me narrow down my choice to these two skis in the original thread (https://www.newschoolers.com/ns/forums/readthread/thread_id/615002/). I'm looking to buy a ski almost purely for park and, with a lot of help from NSers, I think I've narrowed it down to either the Rossignol S4 or the Armada Alpha 1 (found good deals on both).

I currently ride a pair of 189cm 08/09 K2 Seths mounted a couple of centimetres forward of K2's 'all mountain' mark and I love them for almost everything. I'm getting more into freestyle now and want to get something that's a bit easier to throw bigger spins and flips on. I'm looking for something really lightweight with a really low swing weight. I don't ski a lot of rails so although this will be almost solely a park ski, it'll be 98% kickers. I'm 25, 6ft 3 (190cms) and about 205 lbs. With regards to ability, biggest tricks at the moment are double backflips and 7s but they're both a bit hit and miss!

I'm looking at either the Alpha 1 in 182cm or the S4 in 181cm. What are people's thoughts? The Alpha is rockered and has that weird taper so I'd imagine will ski shorter, have a lower swing weight but be less stable at speed and on landings though it does have camber underfoot. The S4 is still apparently quite light though I don't know how it compares to the Alpha. I'd guess that the swing weight might be a bit higher on the S4 as it doesn't have the taper. It's also traditionally cambered so might be a bit more stable but a bit more prone to catching tips/tails. I'm not sure how they compare for stiffness.

I haven't skied either so I'm just guessing all of this! If anyone's had any experience of either or both skis and could make a recommendation, I'd love to hear from you.