how's this for a backup strategy? (ATIH 2011)

Hi
I just thought I'd share the backup strategy I've come up with for my home machine, both to see if anyone sees any potential issues with it, and also in case it might work for someone else in my position:

0. I want it simple simple simple. Safety in simplicity.
1. Home machine, not used during workdays (usually powered down - no remote access/serving)
2. Can't leave it running overnight (small apartment, noisy fans, light-sleeping wife, power consumption, etc)
3. Don't need daily backup, comfortable with several times a week
4. Don't need multiple points in time, just the current state is fine
5. Uncomfortable with black box/complicated scheduling - actually I'd want to touch/administer the backups from time to time manually just for reassurance
6. Backup data about 270 GB, using a 500 GB external FW800 drive (so not tons of headroom, but again I don't need to maintain multiple points in time)

So here's what I'm thinking: Use incrementals custom-scheduled for midday during the 5-day work week (not enough HD headroom for differentials). I leave it set it to do nothing if a task is missed, so effectively I can decide which days I want a backup to run simply by leaving the machine and the FW HD powered up when I leave for work in the morning (I set the task to shut at least the computer down afterward). I'll do this once or twice a week depending on evening use, installs, etc.

Then I just keep an eye on the storage remaining on my FW drive and use to wrap the most recent Incremental with the initial Full.

This probably sounds very simple to most of you guys (that's a good sign if it does!) - but this could be a good approach for an awful lot of home users like me, who don't leave the computer on all the time, don't have tons of storage room, too lazy to run manuals but not to lazy to want to keep simple tabs on what the backup is doing.

Sound like a good plan?