Hi JimK,
Think I'm in the same mood 
...gathering as much info about all the availblable gateways....just to make my final choice.
I've contacted Libellium too for info of their Meshlin. I also had some questions and one of their answers surprised me cause I couldn't find that in the documentation:
Meshlium with LoRa is only compatible with Libelium LoRa modules, as they use a custom protocol.
regards,