I have a Janome 8900 with an 11" harp. I love it to quilt on. It has been a good machine for me and was mid-price $2,500-3,000).
I agree that needle down feature and speed control are nice features that I would consider necessary. I also like the design of the walking foot on the Janome 8900 as I do a lot of walking foot quilting. The FMQ feet on this machine are nice as well. They are different shapes and they don't hop. I find it hard to FMQ with a hopping foot.
It has a lot of decorative and utility stitches that I have used more than I thought I would so that is nice as well.
You really need to test drive machines and see where your comfort level is budget wise before making a decision.