I use the 1/4 with guide and it does a great job of keeping it straight. But my machine also has the markings for the 1/4 on it, which I use as well. The markings on the machine are much longer than on most machines. [ATTACH=CONFIG]398103[/ATTACH]
You can see the markings on my machine from this picture. I don't think any other machines have this ... but I could be wrong too.