Passing along some information for those considering the 6.6.1 upgrade.
We did our first production upgrade at client direction this last weekend, and they are unhappy with the changes on the billing side, and while we are looking with AC for work-arounds, they are considering going back to 6.3.3 this weekend.
<>There is no tool for going back to earlier versions - you are stuck with 6.6 unless you want to go back to your last known good back-up prior to upgrade.
<>You will need to restore the "AC Server" to a restore point before the upgrade. You CANNOT just uninstall/reinstall, as the install makes ~1000 registry/DLL changes that are not reversed. The other option is to reinstall the server OS.
<>The new version of SQL Server consumes considerably more memory than previous versions. Our observations are 3+ times as much.
Sometimes being professionally paranoid pays off, as we have a full image of their environment prior to upgrade that we can revert to, but otherwise we would have to go to a restore point.
We hear that some folks are happy with the upgrade, but users should go in knowing there is no easy way back.
