There have been many issues - perhaps the biggest is the fact that the Apple tools no longer work consistently across different platforms. I have to keep separate versions of source for different OS versions. It shouldn't be that way. Jaguar also broke graphics manipluation (NSImage, and NSBitmapRepresentation) big time. Spent months chasing down bugs when the Apple release Notes for Jaguar concede that there was a change and ("This shouldn't affect anyone!") Ha! They are getting way too sloppy.
They have major security holes that the OS system will not install on many systems listed by Apple as being supported, the graphics drawing is extrmemly inconsistent across Apple hardware; simple code compiled under the new tools behaves differently on different hardware; compiler optimizations are completely broken; the 10.2 server is 25% stable as in previous verions; the mail app in 10.2 won't reliably download my mail. None of these problems existed on 10.1.5. On top of that Apple Developer Support doesn't havea clue - their responses to bug reports indicate that they don't even read them and its clear they've never tested this OS on over half the machines they say support it.
Its the worst release of OS X since the second public beta. I've been working with it since before public beta.
Disclaimer: I'm running OSX 10.2.1 on a PowerMac G3 350 with 512mb of RAM and 40GB 7200 RPM hdd.
All security updates work fine for me
Graphics drawing IS CONSISTANT across the platform. It is your box that has the problem, not the platform as a whole. I have worked for an apple reseller before and the demo units worked just fine. My PowerMac and PowerBook (both G3 models) work just fine. My neighbor's G4 iMac works just fine. My friends' Power(Mac || Book) G4s work just fine. $hit, if it works on my old hardware then it isn't a problem that exist in the wild for most users!!!!
Funny, all of the code I've tried works just fine. Most of the mac users I know are running some UNIX software on their boxes without a problem. I run Python 2.2 and the CVS code just fine along with stuff like NCFTP, SSH and Apache just fine. Same with a few of my friends.
Can't speak for the compiler optimizations because I only have a light knowledge of GCC. Most of my Makefiles are pretty basic.
OSX Server: no comment as I have no experience with it
Mail client. It grabs my IMAP mail from my university mail account without a problem.
No offense, but you sound a lot like an art major I know who installed OS 9 and OSX on the same HFS+ partition then tried to "remove OSX" by dropping all of its system files into the trash. And she called me up crying the night before a MAJOR project was due the next day. Oh and she hadn't printed out her drawing before she decided to rip her OS a new one.