[james]

.comment_text {
font-family: helvetica;
font-size: 1.0em;
}

The default 0.8 is looked awfully small. Are most sites 1.0em or 1.2em?

[Steven]

It's meant to look smaller.

As you can see, it's only slightly smaller on the demo.

It completely depends on the website as the 'em' unit is relative.