I think it depends on your budget to be honest with you. When I was in the market for a new machine I wanted to spend no more than $5k on a sit down quilt machine. I ended up with the Tin Lizzie sit down with the 18" harp and a Juki 2000 and I had a bit of cash left over. I don't regret getting the bigger machine for quilting. I've quilted 2 big king sizes in the past year (and about to quilt my 3rd) and it's heavenly to not have to worry about all that fabric to the right of the needle. I wasn't able to get a firm idea of how much the VQ3000 was. I saw a listing for it on Ebay for $4k so I'm assuming that's in the ball park... There are other sit down machines that are less expensive than the Lizzie - and Juki is coming out with one soon. There's a few others out there including the Bailey ($3k with table included for a 17" harp) which I probably would have bought had the table been available at the time. That would have saved me a lot of money... and there's the Sunshine 16 and one other that I'm forgetting - these are all cheaper than the HQ sit down model and others like the George which is considerably more expensive than the HQ... so if you were thinking of spending about $4k I guess I'm saying that you do have some big options.
I also love my Juki. I'm a speed demon when it comes to piecing now. I swear I get more pieced faster than I did when I was using my Janome. Once I got used to the speed I was unstoppable. The Brother straight stitch machine goes just as fast as the Juki and I can sew through an ungodly amount of fabric layers at once. My record is 18 without even the machine complaining. It was like, bring it on!!
You'll have to decide what is best for you. If you have a dealer nearby you should go and sew on them before you buy anything. This way you can compare and not wonder what it...