Just got mine in the UK, too. Just about got enough charge in it to used on my tube journey this morning. I'm an audiophile neophyte so take this with a pinch of salt, but so far I'm loving it. The only problem I've had so far is that it doesn't read the tags from my AAC files so I'm navigating by folder ATM.
Yep, thats the biggest issue at the moment. They said they were working on it.
50% of the songs on my X3 are in AAC format so only manual browse allows me to use them at the moment.
Some UI nit picks that I can't forget(I was a touchscreen DAP user for 5+ years) are really the biggest downers for me.
Anyway, I'll be getting the Colorfly C4 next month, so I can compare some UI and what not. (although the C4 is going to be stacked with the X5)