I went back to main edition, but while using LMDE, the difference was immediately noticable and i was NOT using the ubuntu fonts...that has nothing to do with the rendering at all...in fact, i was just using the standard fonts that mint use to use for applications and installed the microsoft fonts (ttf-ms core fonts which you have to do in package manager because you have to agree to the license agreement which doesn't pop up in the software center)...and i used the ms core fonts in Google Chrome (my favorite browser)...i think i use Times New Roman and Serif....and it looks great...
Of course you can experiment with whatever fonts you like...but the key is to INSTALL PATCHED LIBCAIRO!
Clem did it for us in the December LMDE iso but sounds like your guy didn't have the time to do it on his...so you will have to add it in manually...
Hope that helps









