The experience of using it is very convenient. You don't need to download a CSS file. All you have to do is choose a simple template design and pick any background, font color, and adjust the width of your blog. You can see the result on my other blog DeejSpeaks.
If you haven't used the template designer yet, better try it now. Do not forget to switch to the updated or new version of blogger because this function is now working for the old version of blogger.