I don't have the field experience, but did look pretty hard at the system a couple of years ago. All the data and the case histories that were provided by Expro (and are available as SPE papers) showed the system to have been successful. We opted not to run it though as the battery life (which from memory was 6-9 months if run on a low data transmission rate). Battery length is totally dependent on the frequency of pressure points taken and the downhole temperature, and for our applications I think we would only be able to get one pressure reading per week over 6-9 month (though I could be mistaken, maybe it was one per day). it wasn't enough data, and the battery life was not long enough for the deepwater application we looked at.
I don't have the contact details for the guys I spoke with at Expro, but they are a smallish team. I'm sure you can send a general inquiry to either team in the UK.