I wouldn't use a tuk-tuk for long distances (e.g. to/from Colombo) though! I didn't find Sri Lankan driving that nerve-wracking (or horn-heavy) compared to the likes of India, but there's still that expectation that, for example, buses will overtake fairly blindly or vehicles will pull out of side roads and you will be expected to accommodate both...

Galle is a wonderful place, with plenty to keep you occupied - but there's a lot along the south coast worth seeing, if you fancy getting out and about without going quite so far.