Please do try to get by a dealer and try some machines. The Jem is one I've heard good things about from folks who sew casually or want a small machine to take to quilting class.

You might also want to look at the Janome 659, which has a more automatic buttonhole that can also be "tuned" for stitch density (I don't know whether or not that's true for the Jem series) There have been complaints about Jem buttonholes, but I can't evaluate the question of machine problems vs. user problems.

One place to compare such machines is http://www.allbrands.com (I ordered a serger from them in May; that went well -- however, I'm still going to suggest that if you can buy from a local dealer you strongly consider that.)

There is one disadvantage with a half-size machine like the Jems -- there is virtually no room to the right of the presser foot, which means you'll not be using it to machine quilt anything very
large.