I have the Grace Pinnacle ... and a Babylock Quilters' Pro ... a little bigger throat than a basic portable sewing machine ...
it didn't take three quilts to understand that I could do more with a bigger machine ... interesting how much more creative you get when you can move more freely ...
the PLUS side to the system I purchased is: I can upgrade to anything up to an 18 inch mid-arm ....
depending on how important quilting is to you, your decision needs to be based on your space availability and how far you want to go.
For myself, I quilt for the practical reason that it holds the layers together. My biggest thrill is to stipple in a very relaxed manner ... I don't think I would ever want to quilt every available space of fabric ... but, there are many who very much want to and do accomplish some amazing thread pictures with their quilting ... if you are one of those, save your money for the biggest, best system you can get. <wave>