Switching from Donncha's Domain Mapping Plugin to WPMU Dev Plugin

Hello,

I'm currentty using Donncha's Dommain Mappinn Plugin v 0.5.1 on WPMU 2.9.2 using parked domains mapped over subdomains and would llke to switch to the WPMU Dev version. I'd like the transition to go as smoothly as possible, so can someone confirm that I understand the process correctly.

  1. I am going to download the new plugin and put it in the mu-plugins directory.
  2. Deactivate Donncha's plugin
  3. Activate the new plugin
  4. Enter the Server IP into the admin options page
  5. (Now here is where I'm confused...) Go into each subdomain blog and enter the domain that is being mapped? Or will this carry over from Donncha's plugin?
  6. I'm done?

Two more questions:

1. If the world comes to an end trying to make this change can I simply deactivate the new plugin and reactivate Donncha's and be back to normal?
2. Do I have to mess with the CNAMEs or A records? If not is there any advantage to using CNAMES / A record instead of parking the domain?

Thanks.