http://www.patternreview.com is a good place to get information about specific machines (including what people have paid for them). You need to create a free account to view the older reviews. Click on the sm/serger category and enter the brand of machine. You then need to scroll through all the different models for that brand to find the reviews for the specific machine you are looking for, but it's worth it.
Edit: Found these reviews of the Pfaff Smarter by Googling:
http://sewing.patternreview.com/Sewi.../Review/1/4390
http://sewing.patternreview.com/Sewi...ns/topic/74226
http://www.stitchedincolor.com/2013/...hine-woes.html
Looks like the Janome would be a better choice! The Smarter seems to have tension issues.