I have a Sapphire, about 4 years old. I got it to do FMQ and I was in love for about 3.5 years. I did FMQ on 5-10 quilt tops. The large throat on this machine is great. Then I got my quilting frame, and put the Sapphire on it. Tension issues and rats nests have been really frustrating. Had the machine in for service in August and the problems are still there. Probably a round of de-linting will fix the problem, get me through another half quilt before it starts acting up again - but the machine is just not built for FMQ on a frame.
In August I got a vintage singer 15-91 and it is amazing... I am using it every day for block piecing. This machine has a vertical bobbin which gives better FMQ performance, in theory.
I have another machine on order (17" voyager) to do FMQ on the frame - a vertical bobbin machine. I really hope it will be a good one!
Over all, the Sapphire should be good for general sewing, fancy stitches and SMALL FMQ projects. If I needed a general sewing machine today, I would go for a used Bernina - maybe a mechanical one if I could live without the fancy lettering.
If you do go with a Sapphire, check out competitive pricing on Patternreview.com. You may be able to negotiate with your dealer :-)