I have the Sapphire 930Q, and I'm happy with it. I tried it at a class, and bought it on a whim based on how well it sewed.

I love it for free motion - it has a floating free motion mode that I find works really well. My fmq improved immediately and noticeably when I started using this machine.

The class I was taking when I bought this was all paper piecing, and it did take a bit of fiddling to get my normal quarter inch seam right for regular piecing. It doesn't come with a foot with a side guard like I'm used to; you line up the fabric with the edge of the foot, and move your needle over to get the width right. By default this is at 1.8, but I found I had to go to 2.3 to get my finished blocks accurate. I taped an old hotel room key to the bed to give me the edge I like to butt the fabric up against.

One thing I don't like is that you don’t have infinite control over your needle position. For example, in playing with my quarter inch seam, I can set the needle position at 1.8, 2.0, or 2.3, but not 2.1 or 2.2. In practical terms this probably doesn't matter since that 0.2mm is such a small move, but I would like it if I had the option.

I really like the extension table for piecing. It curves down in front, which doesn't seem important, but makes it much easier to see and to get pieces lined up. It's hard to describe until you try it, but I really like it. However, I find this makes FMQ slightly more challenging, since I use the Martelli gripper ring, so I can't apply pressure to the front of the ring because the table slopes away. With Machingers I don't have a problem. I'm planning on getting a table for the machine to sit in, which will eliminate this problem.

It took a bit to get used to not having a lever to raise and lower the presser foot, but now that I've adapted I love it. The foot pedal tap system is really great.

The lighting is good, but I do occasionally need an extra lamp to illuminate the fabric a few inches in front of the needle (I was sewing with similar tones in a dim room). Most of the time it's fine, and the led's give excellent light. If I wasn't sure whether two pieces were the same colour or not, I would hold them under the sewing machine light, and it was as clear as daylight.

Try it and see if it works for you, of course, but I do like mine.

I have owned the Sapphires 870 and 875, used to sell them new. I have been sewing since I was 9 and quilting for almost 30 years. Learning to FMQ with both machines took me a few weeks. I have since traded in my 875 for a much improved Pfaff Quilt Expression 4.2, has the built in walking foot(IDT), very much like the 875.
Sharon in Texas

I have a Viking Designer Royale, and accessory feet are available through your Viking dealer. There is the Clear 1/4" Piecing Foot with Guide, part no. 412927445. It fits all codes, and the Sapphire 875Q, 870, 855, 850, 835, 830 are all a code 7. I also have a Pfaff Performance 5.0, and there are accessory feet for piecing for it as well, a 1/4 " piecing foot without the guide comes with it, and there is also the Clear Quilt Foot Right with IDT, 820881-096, and the newer one Perfect 1/4" with Guide which has a little wider hole for moving your needle in order to do the scant fourth inch. Part no. is 821063096 and works on Pfaff coded machines B, C, D, E, F, G, J, K. Love this foot, but have to always remember to move needle over because machine defaults to center needle when machine has been turned off.