Since there has been no updates for Mr. Bjørn Grønli's spreadsheet, I chose to continue his work.
The link is https://docs.google.com/a/hqcodeshop.fi/spreadsheets/d/1ZJsy0q-8tmR8m32d1bCHkSv1neGVtA5v5TU4qVczH0Q
I did try out a number of SP104 and SP105 T-mobile (German Telecom) firmwares and found that they are really poor. 3 Italy was a pretty poor firmware, as I had problems logging in! Polkomtel's SP103 was a solid performer, but after a round trip, I went back to Telia's SP102.
Please drop me a comment if something is wrong or new columns should be added, or if I'm missing a firmware in the list. My idea is to try to keep this up to date with firmware information and I will appreciate any help from you.