I would Google to get more information about both machines. Also check
http://www.patternreview.com for reviews of the specific models from actual users.
Ordinarily I would choose Pfaff over Juki, but in a quick scan of a few websites with Google, it seems to me the Juki has a bigger harp and seems to get good comments from users (as does the Pfaff). One of the websites indicated the Pfaff 2.0 is geared more towards embroidery; 3.0 and 4.0 are geared towards home sewing and quilting (although not sure which is which).
Oh, and in answer to your original question, I use my (now getting ancient) Bernina 1230. Love its purr and total reliability.....