Jack, Thank You very much for feedback. Now I feel safe to upgrade to AC 7. My main PC is not real server (REal server implied special CPU, Motherboard and appropriate operating system) - It is just dedicated computer with a lot of memory under my desk.
It connected via router to four other computers (not more then 2 of them are being used simultaneously to receive and send data to AC). AC doesn't quit every 3 days however some services are being stopped with no reason. These services are responsible for automated backup So I need to check it every morning via VNC from home and run backup manually. Another problem that I have Upload of my backup is failing every other day. AC offsite backup doesn't have autorestart feature so my huge backup file(~15 Gbytes)take 8-10 hours to be uploaded. It is important that AC executables to be added to exceptions in Filrewall and antivirus settings.
I can't say anything about updox. I used it a lot when I neededed to import my paper charts and now I keep it only because it is necessary for MU - patient portal feature. Thanks again for the feedback