adamadam said:What is this peace of mind you speak of?
Your present lenses can be used on 20D/30D and future lenses too, whether they are EF or EF-S. I think the only issue is if you buy EF-S lenses and decide to change to FF body in the future, then your EF-S lenses won't be good for you (but there's nothing wrong with having 2 bodies) hee-hee-haw-haw-haa-haa-hoo-hoo
Hee.. Wat I meant was with 5D, all EF lenses can be used but not EF-S. If I get a 30D, or 20D 2ndhand, I should be getting a 10-22 for those wide angle landscape shots. It's EF-S. The 17-55 is EF-S also and is worth considering. These lenses are doing pretty well now but as some say, FF DSLR prices will drop and by then, I'm not sure what the value of EF-S lenses will be. Of course, some also say, Buy now and shoot, worry later, can always sell off then even at a substantial loss.