There was a long thread about this some time ago. The desirable cutter is the one that is 24" long; a lot of people like that one. It has been discontinued and I think the only place that still has it online is Nancy's Notions (for about $60). The one at JoAnn's is also made by Fiskars, but it is much smaller.
From what I remember from the other thread, the 24" inch one can be good for people who have difficulty cutting strips with a rotary cutter. The smaller one did not have a lot of fans. It was mentioned by some that you have to use quite a bit of pressure when using this kind of cutter; not everyone likes that. However, it is a very safe cutter to use. One poster said it allowed her children to cut strips safely. Most people who had the longer cutter really liked it.