Professionals usually hold off on OS upgrades for exactly this reason.
had my MBP not crashed recently and fried my old drive, I would have definitely stayed with SL simply due to fears of upgrading. as a professional, relying solely on my computer (and thus operating system and programs) I strongly steer away from upgrades, no matter how awesome they might be, for at least for a year or two.
I simply cannot afford to lose the functionality of application nor can I afford to suddenly pay for upgrades. not to mention the slough of other small programs I use to help my work that I got off the internet for a buck or two, that certainly will not be in compliance.
it's idiotic to expect applications and operating systems to all be on the same wave length.
though since we're ranting on this thread.. for no other good reason but just ranting, it took me a few days to figure out how to turn off the stupid, idiotic, ********n(!!) retarded, way of sorting emails into conversations in Mail in Lion. wish they would make two versions of Mail: one for working professionals who need to actively manage their inbox and archive emails. and the other for the house wives who receive only the wanted emails from people they are expecting to receive them from.
Mail completely ignores the fact that while the email may have come from the same sender (uh-oh, same company!), that the recipients email address is completely different on each one. Thus hiding new emails under months of old emails pertaining to a completely different matter. even the sorting within those conversations is illogical. Just because gmail did it, wish Apple would be smart enough NOT to follow google's idiotic suit.
In fact, let's rant more. my biggest issues with my mac and working smoothly on one, relying on it to run my business has always been the piss poor job apple does when it comes to integrating with gmail (and google) and the MAIL application in general.
I have always had issues with getting my mail, sending mail, having weird issues like supposedly the password/username is suddenly incorrect, or the server is suddenly offline. and don't you dare to run your gmail into your iPhone cause before you know it, you just have to change your email address because the iPhone will reject it permanently. This has happened.
Not to mention the new slough of problems happening with the mail integration in Lion. It blows me away that with all the fantastic functionality of a Mac as a working professional's computer, that Apple continually chooses to ignore such a fundamental part of business communication as MAIL!!??? when I was still under applecare (and was naive enough to actually call them) and spent several hours on the phone trying to fix these problems with my mail, I was told by Apple that the problems I am having "do not exist", but I could find lots of people with the same problem by simply googling the issue.
sorry, I ranted.