Lion is teething
Should you upgrade to Lion?
Not surprisingly, I have been getting this question since Mac OS X Lion 10.7 was released in July, and with the recent release of iOS 5, that has only increased the number of queries since iCloud is currently only supported on Lion, though I still hold out some hope for fuller support for Snow Leopard (10.6; iCal syncing seems to be working, but not Address Book).
My recommendation remains to wait.
Why?
At first, there was still a lot of software that hadn't yet been updated for Lion and the significant changes under the hood made this release a little less predictable (than, say, Snow Leopard, which I enthusiastically recommended almost out of the gate because of the obvious improvements in speed and polish). While a lot of third-party software has been updated since the summer, there still remain apps and drivers that are not updated, so my caution still stands. If you have a question about Lion compatibility, check out the vendor's site or the crowdsourced RoaringApps site.
But the other, bigger reason has to do with lingering speed and stability issues. Safari (5.1) has been especially unstable, leading me to recommend Google Chrome as an alternative until Safari regains the stability it enjoyed under Snow Leopard. And overall, while there are many refinements in Lion, they are, in my mind, still offset by steps backward in speed.
Until a future release of Lion (hopefully 10.7.3!) fixes a majority of the issues I currently experience, I will continue to recommend waiting.
If you do want or need to upgrade (say, because of iCloud), I recommend upgrading your RAM to the maximum (8GB for most MacBooks since 2009). Solid state drives (SSD) continue to drop in price and are a great complement to Lion's hunger for resources.