I have an interest in IR photography having tried the external filter approach and dedicated DSLR with hot filter replaced. Have found both these Canon models for sale on fleaBay for less than the conversion cost. The G5 has a 665nM filter which allows some visible to pass giving 'faux' colours and the S70 has a 715nM which is mostly IR giving the more mono look. The S70 is a newer 7MP camera compared to the 5MP G5. I'm leaning towards the S70 but open to suggestions.