This update may have come too late for some folks I know but, for me, it is VERY welcome. Of note: It hasn't locked-up while multitasking during encodes, it continues to play when I fast-user switch (sweet!), and I love the 256 kbps. My interface fonts no longer turn to unrecognizable black hash. Even better, iTunes will now walk and chew gum without an (apparent) freeze.
I am, again, buying in the iTMS.

Warning--Old Beefs: 1) I used to try to sort lists and update info files while encoding CDs only be have the program lock-up...frequent but not constant. (Fixed) 2) Burning a mp3 CD of purchased music for my car SUCKED. (DRM free fixed this) iTunes has been ill for years, suffering from being a ported and revisioned 3rd party product. It was inconsistent with Apple's own interface guidelines; e.g., I have to hold the Option key to make the green blob act like it should in one window but another iTunes window allows the green blob to follow the Apple guidelines.

My rule of thumb had always been: "iTunes sux...just a little less than the other options." Not a great showcase for Apple quality. And ALL of my Window co-workers are moving away from iPods because iTunes doesn't "Just Work" for them. They'd rather drag music into the generic "player-as-a-flash disk" and have it accessible through the player's interface. It doesn't matter who's fault, the perception is that Apple hoisted iTurd as a must use appliance with their iPod. Finally old grip; using the customer as a beta-tester is not great for business.

But I am grateful for Apples continued development and this version in particular.