Safe sleep on 2009 iMacs

Hello everyone!
I'm on the edge of buying a new 2009 21,5' iMac, but I just discovered that one of the features I was more looking forward to, Safe Sleep (the ability to save ram to hd before a stop, so that if there's a power outage while the mac is in stop I won't lose my work), is enabled exclusively on Apple Laptops.
I really need this feature and I discovered that it can be enabled on iMacs using a shell command, but I'm not too happy to begin my "Mac life" with an hack.. so, my questions are:

1 is really safe sleep only enabled on laptops by default
2 if I use the hack (sudo pmset -a hibernatemode 3) to get safe sleep on the imac what I risk?
3 what happens if I use the aforementioned hack and then in the future upgrade osx with one of it's "service packs" regularly released by apple?

The place where I live has regular power outages during the night and I need the ability to safe sleep my mac, otherwise I would have to shutdown it completely each time... I'd prefer safe sleep over hibernate as safe sleep restores istantly if there isn't a power outage

These may seem stupid questions, but coming from vista where hybrid sleep (microsoft's clone of safe sleep) is available on every hardware I never tought safe sleep would be a laptop only feature Now I want a mac.. but I NEED safe sleep and I don't want to hack...

Well HERE is a free download for safe sleep. You can get it as a app now. No need to hack trough terminal anymore ....

SafeSleep... Mac OS X 10.4 improved a little-known feature of Mac OS X; in a low-power situation the contents of memory will be saved to the hard drive and the computer will shut down. On other Operating Systems this is a standard feature known as Hibernation or Suspend-to-disk.

SafeSleep lets you quickly and easily put your laptop into this sleep mode on demand. I have been using it for several months without any problems. But note that this usage of the functionality is not officially supported by Apple.

Hope this helps your situation

cheers

What you really need is a UPS.

Safe Sleep might help, but it is not a perfect way to prevent damage to your system or loss of data. If you have a desktop and live in an area where power outages are frequent, you need a UPS, no two words about it.

I second that. Here in the Dallas - Fort Worth area of Texas we get some pretty nasty thunderstorms which usually result in power outages and power glitches. An UPS is an absolute must have. The nice thing about an UPS is not only the protection from power outages but the smoothing out and removing of ripples on the power line that can damage electronic equipment.

Buy a good one.

Regards.