I am at the point where I really start to hate this cube.. LOL I will try that. Also C4U screws and springs? Or just the core?
I only used the C4Y core. I Kept the Fangshi springs and screws as my C4Y screws look much shorter, and I figured the Fangshi springs are the right size for the cavity inside the Fangshi centre pieces. I think my C4Y core wasn't pre-threaded, so the screws made their own new channels in the core (or just fit very well anyway).
I still haven't decided whether I like this cube yet. I changed my colour scheme, which is throwing my recognition off a bit and slowing me down (not the cube's fault). I'm still finding it a bit too squishy for my taste (at least it it holds its shape properly now after the core swap), which may suggest it's less forgiving of sloppy manoeuvres - my various Dayans let me get away with a lot, it seems.
This is mainly a problem for algorithms involving a lot of fast flick-type movements, such as for one of the four 'awkward shape' OLLs - R2' U R' B' R U' R2 U R B R' - on a Guhong or Zanchi, I have a really nice flow with no gaps between any of those moves, but on the Fangshi, it catches if I'm not sufficiently precise. From a static position (the standard 'corner cut test'), my Fangshi's corner cutting is great on all faces from all four positions, but mid-algorithm, meh. It'll take me a few more weeks to decide what i really think of this cube though, and I'll probably get the smaller version when it comes out, as the 55mm DIY black Zanchi I got the same day is already my favourite cube, the size is perfect.
PS. This is the C4Y core I'm using (aka "MHZ"):
http://lightake.com/detail.do/sku.MHZ_Core___Screws___Springs_Set_(New)-29962