This is a good trimmer specially for the price. There is no wobble in the ruler which means It cuts straight. I cut 210 gsm paper and cut was clean. The ruler has a slight raised area on one side which makes it easier to hold down and cut the paper. It has both inch and cm measurements, which is brilliant as I tend to use both. The angle markings are very useful. I use them to create the points of arrows and labels. You can cut a minimum width of 2 cm or 1/8th less than 1 inch paper strip. The extended arm locks in place so no worry of it getting in the way or accidently breaking. There is negligible missing measurement between the extended ruler and and main area, which I have heard can be a problem between some other trimmers. There are markings on the 4 sides of the blade holder, which along with the gridlines helps you make precise cuts between a paper.
So why only 4 stars with so many positives. There three things that bother me only one of them being significant. Firstly, it makes a weird and loud tick noise every time I finish cutting paper. I think it happens because of the release of pressure which I have to put on the blade to cut the paper. At first I thought it was the cutting ruler but now I know for sure it's the blade holder. Any how I can learn to ignore it as long as it doesn't break.
Secondly, it creates a micro lip at the bottom of the cutting edge of the paper. I can't explain it any better. It's barely noticeable but unfortunately I notice it everytime. It's not a deal breaker though.
Lastly, There is no way to lock the cutting ruler of the trimmer. This means if tilted to side it flips and exposes the blade. Now the blade is still a bit inside the holder but I would have still prefered if I could lock the cutting ruler.
All said and done I like this trimmer and am happy with my purchase. Now I wish I had bought the extra blades but I wasn't sure how good it will be.