The Canon Powershot S70 would be great if it did not have so many problems!  In terms of functionality it is similar to the Canon Powershot G6, except for a compact body and lens. This is where the corner softness and purple fringing not seen on the G6 come from. Additionally the flash is too close to the lens which causes red-eye (even with red-eye reduction turned on). Focusing is slow and misses apparently occur, this has been reported by more than one review listed below.

The S70 can still be a good choice for those looking for advanced features in a compact camera, just expect to sacrifice image quality. If size is not so important, the Canon G6 is better. For similarly sized cameras with less problems, see the Canon A520 or Fuji E550.