Everything I'm releasing is specific to Onity. I can't speak to the security of any of the others, as I haven't looked at them yet, but I'm planning on doing so in the near future. Next up is most likely Ving, though Timelox is a really clever system, so that could be fun.

The room I'm in has a Ving lock. I witnessed it being reprogrammed by hotel staff when I was having problems opening my door.

Ving may have security flaws but I'm assuming it will be a bit more expensive to exploit.

I can't speak to the actual security, but I know that it requires a contact card inside the slot to actually program the lock. That's not something you can likely build for a couple bucks in parts at Radioshack, so at least the barrier to entry is higher.

At least, higher. If you were in the business of robbing hotel rooms, I'm sure a onetime fee wouldn't be much of a barrier. Keep the small-time thieves at bay though.

I wonder if you could legally squad empty hotel rooms like this?

Exactly my point. :)