At the very least, I would not upgrade until I wanted software or a feature that required Lion. With a heavy duty program like Logic, I'd be even more hesitant. If it ain't broke, etc. I only upgraded to Snow Leopard a couple months ago!
My experience with mac upgrades isn't flawless, but nearly so. I'd be more concerned with a PC. That said, don't upgrade without a solid backup of your current system and enough time to go back if the upgrade screws you.
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