Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Returned it; couldn't get used to index finger trackball

I had this less than a day when I returned the product and went back to a traditional thumb-based trackball. I couldn't get used to the placement of the ball under the index finger and just couldn't get the kind of pointer precision I needed. Plus it felt uncomfortable. A lot of reviewers love this item but any individual should try it out first in an actual work environment to see if it is right or wrong for them.