i can add some perspective to this.
i spend a lot of time in sydney and so only knew cx's biz class seats from their a330 aircraft as that is all that they now fly into syd. i'm 6'2" and sleep on my back and found their new biz class product uncomfortable as both of my feet would not fit into the wedgy end of their new biz class jump seat (or whatever that triangular shaped bench thingy is called). this meant that one foot was always forced to rest on the elevated raised hard ledge that borders seat whenever i would stretch out. this is uncomfortable for me.

i recently ended up travelling in cx's new biz class seat from jnb-hkg. as soon as i reclined to sleep, i discovered that cx's new biz class seat on a 747 is quite a bit longer than the ones they have in their a330. in the 747 seat both of my feet can can fully extend and sit very comfortably flat without touching the end of the ledge around the jump seat. i find the new cx biz class seat on the 747 very comfortable and sleep very soundly in it. so i am a new convert to liking the new cx biz class seat--just not on the a330 aircraft.

my perspective is that if you can avoid the a330, you probably will prefer the new cx biz seats to the new sq biz ones (which cramp my legs even more than the cx seat). even if you cannot avoid travelling on an a330, you might still prefer the cx seat if you are not too tall.

also, i think you will find cx's customer service hard to beat compared to the sq service you currently have. as others have mentioned, when you are gold or diamond, cx seems always to find a way to get you on the flights you want to be on. i was very sceptical about this when i first decided to switch, but even as a gold (when i was climbing the cx ranks) they always came through. i finally decided i could trust their "wait list" when i as trying to get a biz class award seat for a friend on a very complicated routing from australia to hkg to south africa to hkg to europe. none of the flights were available when i called. but cx put me on waiting lists (i remember thinking "yeah, that's a clever way to get me off the phone"). but, much to my surprise, cx managed to clear every one of the flights--calling me each time one of the many segments cleared to update me and give me the status on the remaining sectors. this was before the "new economy" hit us and was back when premium classes seemed to be always full.

i would suggest that if you have elite status with sq, fax the marco polo club a copy of your card and recent travel statement along with a letter stating that you wish to transfer from sq. i believe that they will elevate you to the equivalent status in the marco polo club (they did with me).

i would encourage you to switch to cx. i used to fly sq a lot and although they were very good in comparison with us based airlines, i found them to be overrated. i grew to feel that their premium class service was a bit too shiny and rehearsed to be genuine and i found their service desks to be unyielding and at times arrogant when i found myself in a situation with them that wasn't described in their rule book and required them to think on their feet. while by no means perfect, cx has earned my respect and it's a nice feeling to truly believe that the airline you patronise really does value you as a customer.

one word of advice from my hard experience. the hold times when calling the marco polo club can be egregiously long. once you attain gold or diamond level with them you automatically jump to the head of the queue so it's worth the effort to try to get them to match your sq status if you can.