Hey all - We have a few mid-2009 MBAirs lying around the office (C2D 2.13GHz SSD, 2Gb Ram, etc.), and have run a few tests on Lion vs SL that you might find interesting. These are developer machines, so we typically change out OS configs and app installations to see how the hardware performs under different environments. Recently we did a simple check of Snow Leopard (10.6.8) vs Lion (GM Dev preview), and got a weird result. On a clean install of SL with nothing added to the box except Geekbench, the MBAir got scores in the 2600-2700 range, every time. But the same machines, running clean installs of Lion GM, got consistent scores of 1800-1900. Now, we’re not hardware geeks around here, so I’m not sure I can give you an intelligent interpretation of those tests. The point here, though, is that we’ve read in many places that a 2Gb RAM MBAir runs Lion beautifully... but in our case, that’s clearly not happening. Or, it’s sort of happening; the OS runs, but the machine slows down, and we get lots of fan spinup and kernel-task process overloads. So our (admittedly anecdotal) conclusion -- watch out for Lion on current MBAirs, or at least the 2.13 SSD revs. Maybe someone here with more hardware savvy can comment on what’s going on, or if our test results are just anomalous to the real truth...!