I tested some other GPS receivers today in Brussels, Belgium. And never I was able to get more than 7 locks (although I see around 10-11 satellites)! I tested the Haicom 204, The Royaltek BlueGPS and mine with the antenna soldered on. They all have the same reception.

So now I am having 7 locks, and navigation goes excellent. I advice everyone to solder an external antenna! It really isn't that hard.