I purchased the 6600P about 2 months ago, but I paid 1049 for it. Its a very good quality machine and I can recommend it highly. The new Horizon 7700 looks like a very nice machine, but it is more $$$. It all depends on what you're willing to spend and what you want out of a machine.
What Viking model are you looking at for 999? Vikings really are nice machines, but then again, you need to decide what features are important to you.