Absolutely... even if the standard said explicitly to expect -1, 0 or 1 I'd still use <0, ==0 or > 0 as my test when sorting... Simply because there are compilers out there that do not follow the standards or pre-date them.
(Not that portable code is an issue with me personally... Believe me, nobody will ever see the source code for any of my larger projects without handing over a LOT of money.)
thank you very much for the explanations everyone