As you can see the font in the Windows V5 client font is fairly smaller, and doesn't look bold unlike the V6 client. On Zodiac I had to modify the zoom values of font's shown with images by 0.1 and TextCtrl's fontsize by 2 to emulate V5 fonts as best as I could.
The font is nice, but the increased size and boldness to it is what's causing the problems and disgust/resistance most players will have with it.