Yes, the new size is harder for me to read. It can't quite put my finger on it, some fonts are just proportioned such that they become hard to read. I can't quite tell what it is, but upon closer inspection I think that it might be the inter-character spacing. If you look in my example at the word color and camera in the first line you see how much smaller the distance between the co and the ca is in the new font. So it looks like that the characters may be larger but the space between them is smaller, causing me to have more difficulty making out the words. I can read it, it just takes more effort than the old font did.

My browser IE 6.0.2 is set to View > Text Size > Medium. Just like it has always been.