I lost some beloved apps, particularly YousendIt Express, iStat Menus and LCD Scrub. I expect I will soon see updates.
I lost my monitor calibration, but the install caught my EyeOne Profile Reminder in the Startup and installed Rosetta without prompting. Calibration worked fine.
I downloaded updated drivers for all my printers (an HP 2015, and Epson 4800 and R200) and things worked fine (the R200 was having problems without an update). I think the new 4800 driver fixed my printing problems in Photoshop, and I can finally print through CS4 and it looks like what's on the screen.
My Nikon Coolscan 9000 fires up with an alarming message--“A minor error occurred initializing the program”--but it works fine. An update to v4.0.2 hung up, and Nikon explicitly says that 10.5.x is not supported, much less the latest. The Epson 4870 scanner works fine, with an updated driver.
I needed to buy the latest Parallels 4.0 so I could still use my residual Windows programs. It works fine. I also needed the latest version of NeoOffice, and a patch to cover Snow Leopard.
What is probably a real bug is a problem with sound settings. On a reboot the System Preferences—Sound reverts to the internal speakers, and I have to manually reset it to Line Out. Every time.
My biggest issue is with Photo Mechanic, which is having issues with not launching at all, or not launching on card insert, or not automatically opening up an ingest window. I am having none of these issues on the laptop, so it's something in the ecology of my desktop machine. Camerabits is being extremely responsive to my problems, which is typical for them. They're a great outfit.
Other than all that--everything is faster, leaner, cooler. Someday the speed bumps will end, won't they?