Does anyone else have this problem? It seems that after I upload a photo it loses it's sharpness and colors seem less saturated. Why is this?

I think it's because the max width of the image is 720px. Depending on the percentage it needs to size down, the photo can have noticeable flaws. I usually make a special copy of my photos at 720 so i'm in control, not the resizer. Once uploaded, I just delete them from my computer. *Note: 720px is the lighbox (expanded) size, not the initial presentation, which is 500px.

This may or may not be your problem, but this is what I've run into.

is there a max height as well? i had those same problems as were mentioned by the op

well. i tried posting a photo with the width set to 500pixels but it still suffered the degradation. i don't know what the story is with this. it seems to be worse with photos of people for whatever reason.

anyway to show examples?

I could email you the jpg I uploaded and you could compare to the image that appears in the browser. Msg me your email address.