What type of use for your new investment?
Do you piece alot? I have found that quilt classes usually require alot of piecing....so the auto thread cutter is a critical feature for me. You usually get the needle up needle down on most machines these days, knee lift is always good. If you are interested in any Janome machine, you can go to janome.com, select a machine then click on comparison for two other of their machines....it will list out their features so you can compare. For example: Janome 6600 has Accufeed, 1000 Stitches per minute, 7mm stitch wideth, 150 decorative stitches, One step buttonhole, Auto thread cutter, needle up, needle down, and start top button for sewing without a foot control. Then you can put in two other Janome machines to compare those features. Take a "quilt sandwich" to various dealers and try it out on the various machines,,, compare price and service history (service tech at the store will tell you how often he sees certain machines) look for the features you want and will use the most. Then go for it.
Happy hunting
Have Fun
D in TX