Hi Uwe-
Hope you are having a great holiday.
I used the Iridium GO during the Annapolis to Bermuda Race - it worked well.
This unit is a hot spot that allows up to 5 users to connect with their iPhone, iPad or Android device. Very convenient as it acts juts like a smart phone (with specific apps you use).
In my case, I used a small GPS style "button" antenna to improve performance a bit (bought on line from third party companies for a good price - about $50).
This was all a temporary set-up. For something more permanent, Iridium makes a fixed antenna kit.
I found that voice calls and text worked very well. E mail also worked well and I was able to pull down GRIB files and NOAA weather maps. Even sent out a picture or two.
As far as I know, the Iridium data rate is 9.6 kbps so I am not sure where the Pilot is getting 130 kbps plus - may be the bigger antenna or they are stating an equivalent thruput rate assuming compression.
I think you can pick up an Iridium Go plus hard mount antenna for about $1000.
Rick
S/V Celerity
2003 Beneteau 473