Tallchick - One thing I admire in particular about the Jukis is that they seem so well thought-out. Everything appears to be clearly marked for threading, the manual is clear, and there are other features such as the notch in the hand wheel that lets you know when the needle is in the highest position. Even the carrying case and accessory boxes seem to have been built with convenient storage in mind. That is why overall it seems to be more intuitive.
I'm sure the Janome isn't the most complex machine out there, however. I've found with my hobbies that the less time I have to spend setting up equipment, the more likely I am to actually work on something. (Or even start in the first place.) BTW, throat space will not be a huge factor. I'm not planning to make very large quilts.