NXE, XMB, and Blades, oh my...
Couple of things.
I totally agree that the current situation with Disks is stupid - as an original 20GB purchaser, I find myself with only 3GB spare, not even enough for a single HDD Game install, but there are a few things coming up to lessen the blow.
First, Microsoft are offering a choice of either a free 512MB Memory Card or a 20GB HDD for $20 for owners of diskless Core and Arcade machines:
http://www.xboxstorageupgrade.com/hh/web/home/hhauthentication.jsp?ssLocale=en_GB
Second, coming out tomorrow, is the £50, 60Gb Starter kit - this includes, amongst other things, a 3 Month Live subscription and a 60GB Hard Disk. Given a 3 month live subscription is worth around £15 (And you can use the code to extend an existing subscription by 3 months), you're getting a 60Gb Hard disk plus other goodies for £35, which I suppose is a livable price...
http://www.game.co.uk/Xbox360/Hardware/Accessory/~r338570/Xbox-Live-60GB-Starter-Kit/
I've been playing with the new interface all night - you may not like the style of it, but one thing everyone will like is the responsiveness - The old blade interface was creaking at the seams, and most users I'm sure got fed up of seeing the little xbox icon, waiting for stuff to load just to get playing.
So far, NXE Has been almost instantaneous on all fronts - each section loads very quick, no waiting for boxes to populate, and the re-jigged marketplace is much better at handeling the ever-increasing amount of content it now holds.
Owning both PS3 and 360, I'd say NXE is a worthy rival for XMB - it may be a little less stylish, but in terms of function, the two are pretty much on par.
...Besides, It's not like you've got a choice to stick to the old Blade system.
So far, the only problem I've had is that the system locked up when pressing the back button from looking at the friends section a few times - anyone else had that happen?
Disclaimer: I'm not a Microsoft Shrill - Just a gamer who was up all night testing this, and wanted to spare some others from the research.