I thought that was just me! I found that reducing the font-weight seemed to me to make it look a bit sharper on my system. I also dropped the font size a bit but that was just personal preference.
userchrome.css
a[data-type="2"], a[data-type="5"] {
/* sidebar - notebooks (2) and tags (5) title text */
font-size: 12px !important;
font-weight: normal !important;
}
I also added a few 1.2.x related "tweaks" to the customisation wiki page if any of them are any use to you.