mine shrank a bit, but the original sizing seems a bit dodgy to me.
i have the skin200 baselayer and the T-shirtesque superfine190. the baselayer is the small but the t-shirt is large, ok so the fit is a bit different, but not that different. the large baselayer i tried on absolutely drowned me - it would only have fitted an orang-u-tang with a 55 inch chest.
if you know folk in australia or NZ get them to send the tops to you as gifts (for customs reasons) because they are about a third to a half of the price of tops in the UK. i got one short and one long-sleeve baselayer and two T-shirt designs for about £120.