Sorry about the delay - start of school here in the Philippines and this is the first year I have four kids in four Different schools! College, high school, grade school and a grade school for gifted children! Actually it is my gifted 9 year old that writes all my code (joke only!)
I have had this running on the live sites:
The Full Gospel Business Men's Fellowship International
My technical blog
A health and healing site (New LipHe or New Life)
This is ONE install.
I actually have a couple dozen sites running in this mix - these are live sites as the last mod is so stable. However these are low to medium traffic sites. It should not make much difference though.
I was not able (meaning no timing difference) to determine any difference in download times on sites with or without the mod - it is just too small.
I would NOT recommend the first or second attempts, as there are not as stable and I will NOT be supporting them in the future. The one I recommend is Version 2.0, The Ultimate WordPress MultiSite, WP Multi Network, Atahualpa Mod
If you are running this on a live site please report it HERE - WordPress MultiSite, WP Multi Network, Atahualpa Mod, Ultimate Working Sites
The reason I recommend version 2.0, even if you are not using logos and favicons, is because the way it handles the code. Also it is a much easier mod and this is the track that I will release new files for (just paste the file and forget it!). So no code finding and modifications.
Likewise, these files DO NOT change the default code. Meaning whatever you have working (the same favicon for all subdomain sites, and I'm not using a logo) will continue to work with no change! If later you want to add a favicon to one site (or all) you just make the change to whichever site you want... Same with a logo image.
CHECK THIS OUT!
One of the wonderful things about Atahualpa is the ability to run multiple copies or multiple versions!
For example if you have one loaded in a folder called atahualpa you could load another copy in a folder called atahualpatest, atahualpa2 or atahualpamod. Then use these side by side, even on a live site, for testing. Just activate or deactivate as if they were different themes as needed.
Let's say you load a folder called atahualpamod with exactly what is in your atahualpa folder. Make this easy mod
and then in WordPress Admin switch to the "atahualpamod theme."
What I actually do is rename atahualpa to atahualpaorig and put the mod site in as atahualpa. If there was a problem with the mod theme (which I have never had) it takes only seconds to switch it back!
When you load this mod, you will NOT see any change in your site. The Version 2.0 mod just ALLOWS you to configure things differently. Until you change the configuration your site will not change. That is one of the real beauties of this mod - no change until you want it!
I looked at your nozzl site John and I do not believe you would have any problem with this mod at all.
If you choose to use the older mod, you will need to remember you must find and modify each line in newer versions of Atahualpa. I will for my own sites, be releasing a new version of the mod files for each new version of Atahualpa and I hope at a future date this code will be merged into the Atahualpa code base as it solves all multisite, Multi Network, and WPMU problems as well as adding a feature for single sites.
A bit of news is that Atahualpa with this mod (ver 2.0) could be approved for use on WordPress.com - the free WordPress site and there is some discussion over there about doing this.
Many people have suggested / wanted Atahualpa on WordPress.com but till now the position was that it would be too difficult to adapt to the MultiSite / Multi Network environment. The sites listed above provide proof of concept of running Atahualpa in the the MultiSite / Multi Network environment on WordPress.com
So maybe if we get this code merged into Atahualpa then all the people on WordPress.com can enjoy it also!