I have had one for almost 5 years. It has always worked.
It gets us our weather data everyday we are offshore. Of course data transfer is “slow” what do they expect? From initiation of the call to complete download of our grib files takes 4 to 10 minutes depending on the size of the transfer.
We have not often used it for voice comms, but it has worked when we needed it. It’s not a landline quality connection, but it serves.
Either use it on deck as a portable device, or get the external antenna
It has proven a good piece of kit for us. I haven’t heard of people complain about them before. I am guessing poor installation or unrealistic data expectations.