Yup, my black VX has an Axiom motor in it, and eventually my green one will too. I've got an 02 Axiom motor sitting in the garage waiting to go in, just waiting for a handful of things to happen before I can pull the old motor out and get to swapping it. I'd really like to get a full write up written once its done to help sort out exactly what it takes and to streamline the process for everyone else and help make decisions like this easier for others, but for right now I have to play the waiting game with other projects coming first.
As far as noticing any differences between mine and other VX engine bays, not really. Mine's a lot dirtier than most, but thats to be expected. :)
Sounds like to me a rebuilt VX motor is the best option as far as quick plug and play to minimize downtime and worry of reliability compared with an un-rebuilt used motor or taking the time to pull and rebuild yours.