I've been completely happy with the S40 (for about 4 years, and about 12,000 pictures kept), so I'd expect that you'd do just as well with the S80. It's small enough to carry around (though not an ultra compact compared to what's available today), with good features both in Auto point and shoot, and good controls for dropping into manual mode.
I've done prints as large as 8x10 with excellent results, in fact just had two 8x10's printed at Walmart right before the holiday's that came out excellent... Walmart printing is usually my last choice for quality, but needed the pictures right away... I use various online services, mostly KodakGallery (previously Ofoto). I've done some head-to-head tests occasionally sending the same file to multiple services, only one in the last year was Ofoto vs Walmart, with Ofoto being the easy winner.
Though I would recommend that you only shoot in best quality, highest resolution, so that you can always get a print made if you get a shot you really like. Memory and storage is cheap and always getting cheaper.
Bernie