Ive had two over the years. My first was a base with heavy glass cups that fit into the base. It worked very well.
The one I have now makes one large batch at a time. Prefered the cups.
The one thing I recommend is to add a package of unflavored gelatine to the milk mix as the makers make a loose yogurt. I used a store bought yougurt with active culture as a starter also. Unflavored of course.