The pictures it is linking to could be better.

[henkall]

When fetching images it fetches a 130x130 image.

That is very low quality.

try doing somthing like this:

It help me but i have not tested it very much.

Else it is a awesome plugin you have made.

[ErikEklund]

I made a fork with some updates that fixes this (amongst other things) - that version now downloads the full sized image and adds to the post as an attachment. Have sent a pull request for the change, but it's not picked up yet. Until then, you can find my version at https://github.com/ErikEklund/fb-group-to-wp