I find that 1.15 has improved my frames/second, but vastly reduced stability, even with all preferences sliders all the way to the left, antivirus disabled, all automatic updates on the PC disabled, etc.. (which I never used to have to do). I would love a less graphically demanding version (or preference) where I have a lower frames/second but do not crash.
SL has had the good ... or bad ... fortune to attract many residents who are not otherwise gamers, and our wallets are appalled by the need to buy new hardware simply for SL. My current laptop is only 2 years old, and would otherwise last me for quite a while.
Less hooked residents will no doubt simply leave rather than upgrade.