I have a 60D and I enjoy it greatly. I have no near-term desire to upgrade. I would like to expand my lens range with a 10-22 in the near future.
I have the kit 18-135 lens and a 28 1.8 lens. If I get the 10-22 lens, I would have two EF-S lenses.
If my 60D camera fails or I drop it, etc. I would most probably upgrade the body to a 6D.
Who knows what the future holds. Do you think Canon would ever engineer into their full frame cameras the ability to use EF-S lenses?
I hate to invest in lenses that would be rendered useless if I upgraded to a FF body that could use the S lenses.
Plunking down $400-700 per lens gets expensive. You want lenses to be a long-term investment, but with the FF restrictions on S lenses long-term may not happen.