To elaborate on Estel's previous post, not only Hawaii, but MohammadAG and I also run our N900s in R&D mode regularly. If you disable the keyboard flickering battery life should be identical. The only difference, depending on what flags you set, is that sometimes your device might hang instead of spontaneously reboot (as in, some deep system process will crash and normally watchdogs or lifeguard reset would reboot the device - with those disabled, if you choose to do so, the device won't reboot itself during some of those crashes and sometimes you have to pull the battery if it's something important that crashes. The advantage is that sometimes stuff will crash and then restart and while you notice it, your device doesn't reboot on you, which is nice, and the "crucial" process that the system supposedly had to reboot for a lack of just restarts and the device keeps working. Honestly even when it hangs and has to be rebooted/battery-pulled, I MUCH prefer to do that than have the device spontaneously turn off on me. One is just irksome, the other is like a slap in the face with barb wire and poison ivy tangled together.