I've been using it since the VIP. Only noted four or so issues that were addressed quickly (one was a major problem). I now have installed at five clients, three of them are live with it. Starting a sixth installation tonight that has ACSG's Multibin, High Jump's BOI EDI interface and will be installing Sage CRM (latest release). I hope to go live by early June with it. Later this month, I will be looking at client running Avalara, SPS and is hosted in the cloud and one that is on v4.5 with a ton of scripts. I think it is well worth moving your vanilla's plus your minor modified installs there first.