I have two 6600...one for home one for cabin....It is known as the quilting machine from Janome.....the 7700 is the newest and greatest, but I would not trade up from my 6600. Make a list of the features you would like, larger throat plate, auto thread cutter....this feature is the number one thing on my list....a must have for piecing. I purchased a 3160 QC Janome for classes because it was light weight and had the auto thread cutter. Your needs are personal, so make that list and compare. I have purchased numerous machines from Brubakerssewing.com and love their service and honestly in dealing with customers. They are across the country from where I live, but would not purchase from one of my local dealers on a bet. Give them a call, tell them what features you would like on a good quilting machine, tell them your budget. They will honestly let you know the best machine for you. They also have slightly used machines at great prices too. (I have no connection with them...just a very satisfied customer) They have other lines besides Janomes.
It is nerve racking going to dealers to look and try machines. The high end machines are so enticing...but, in most cases, not required to make beautiful quilts. Take a quilt sandwich to the store with you and try out several machines, check your features list and see what the best buy is. Remember, if you order online, whether Brubakers or not....there is no sales tax and usually no shipping. You can research features on machines online too. Just google the brand and model and you can see the list. Best of luck in your quest. D in TX