The first gen meters may not work if you switch companies. They haven't, as far as I know, begun to roll out the second gen ones yet. By "not work" I mean they do not transmit info to the companies. The meters themselves work fine. Ours stopped "working" when we left SSE. The control unit that sits on the table in the hallway still monitors our usage, warns of heavy use, provides a daily/weekly/monthly history on request, and tells us the number of kWhs used. It also provides the meter reading, so I don't have to go digging around in the meter closet with the spiders to get it. Supposedly, eventually they will all contact to a central clearinghouse that will distribute the data to the pertinent companies (I think that's what I read). But the software isn't ready yet that would allow the first gen meters to be polled remotely. I'm not holding my breath on it happening in the next year, or two even. But I do like the convenience of being able to track my usage and get meter "reads" off the table-top control device.
Not sure if this is correct or not, but was under the impression that the gas/electric companies actually own the meters, not the landlords.