01. Budget?
02. Megapixel count?
03. Optical zoom factor?
04. Size?
05. Type of batteries used?
06. Weight?
07. Able to mount lenses/filters?
08. Manual controls required?
09. Auto-Focus Speed?
10. What kind of pictures are you hoping to take?
The A70 costs around $520.. how much does the discontinued C3040 costs?
One big advantage of the C3040 is the F1.8-2.6 lens as compared to the A70 F2.8-4.8 lens. The brighter lens allows u to shoot better in low light conditions without use of flash. It also allows you to shoot with a narrower depth of field effect.
But the A70 is newer with, CF support (which is better and more future proof than SM), noise reduction on long exposures, better movie modes (for fun)..
If the C3040 costs considerably more than $600.. I'd think the A70 is a better choice. Both cameras has enough manual features to allow u to learn..