Linear is a fine piece of hardware, and if you're heavily invested in the z-wave modules, I understand why it would be a reasonable choice.
Unlike z-wave module, Garadget can be used as both home automation module and as stand-alone appliance. It is especially great choice as the first home automation product that can later play nicely with the home automation hubs if needed.
A developer is working on MQTT protocol implementation for Garadget. This feature is high on the list and it will become available eventually one way or the other. For now you can find assurance in the fact that Garadget is an open source product riding on a reliable cloud platform and that you own the hardware - you can re-program it, replace firmware etc.