Ok, brief rundown now that I've had numerous clients update:
The Good:
It is polished, looks and runs slick, some functions perform very well. Snappy - on new macs (ie, those issues this year) really great. Looks great on my wife's.
The bad:
From clients I've discovered these problems:
There is now no way in hell to make TimeMachine back up to a NAS that I've found. This became a minor heart attack for a client with 8 PowerMacs. Still working up a good solution on this.
On a Core2Duo Powerbook, battery life suddenly went about 60% of what they were getting before. We're not sure of what's causing that. It may be a zombie service or something, still a work in progress.
I have never played with Spaces, but I guess it's been removed. Some grousing about that.
iSCSI targetting is not right. Still sorting that out.
I think personally my experience has been very good. Very positive. The issues clients have aren't out of the ordinary or real deal breakers for anyone, they are the kind of thing that does happen in an upgrade from OS to OS.. and they'll get sorted out. The loss of TimeMachine to a NAS sucks bad, but I'm sure someone will figure out a way around it soon enough.
I will say: the download to install thing SUCKS. I have several clients who have as a maximum download 768k d/l DSL Modem service. It's not that it's all they want to pay, it's that's all that is in their area. They can't get faster service if they wanted to. With an estimated download time of almost 2 days, they'll just wait for discs.