There is a big push at the moment to get the boot time for Linux down to a reasonable level. I think that the aim for Ubuntu's next release is 21 seconds which will be good if they can do it but not as quick as the three or four that it takes my laptop to recover from suspend to RAM.
I have not really used suspend to RAM a lot before always preferring to suspend to disk to conserve as much battery as possible. That was until a couple of weeks ago when I left my laptop in suspend to RAM mode to go out, it does that automatically when I shut the lid, and then did not come back to it till the next day. I thought that I had left it on charge but it turns out I had switched off the 4-way with it plugged in. Fully expecting the battery to be as flat as a pancake I just checked the battery before turning the power back on. To my surprise it was fine, loads of juice left. From that moment on I don't think I have suspended to disk since. My uptime now stands at 7 days.
This is the way to do it. I just wish that the laptop makers would look at this as a viable alternative and do the work to make this happend without all the hacks that are required today. Another nice thing would be if they provided a deep sleep function where it could write the data to a bit of Flash memory or disk after it has got down to say 10% battery so that if the battery does go flat the next boot could be more like a hibernate to disk recovery. Another good function might be to be able to say after 12hrs on suspend to ram, push the contents to disk for hibernation and power off.
My only doubt is what are the implications of taking the laptop on my bike while suspended. So far all has been okay but that may be more luck than judgement. My understanding is that it is just keeping the RAM refreshing and everything else is shut off so in that respect it should be not much different to my phone.
So a big thank you to all the people who have made the suspend to RAM "Just Work"(TM) in Linux.