I'm one of those people who posted a negative review of the Sapphire on the internet. Mine is an 850, and it had an appetite for needles and thread nests. However, there are many happy Sapphire owners - and more and more happy owners every day. It seems like Viking may have heard the rumblings of discontent.
In my case, I had a bad dealer who sold me the machine and then didn't want to support it. While I think I am smart enough to learn on my own, after a few frustrating days trying to freemotion on the machine I was ready for a lesson - only they weren't offered.
So, my advice is to buy from a good dealer, take the classes and learn how to use the machine. Listen to other locals who have purchased machines from local dealers - you'll find out who will stand by their product and who won't.