Open comb versus safety bar

I still consider myself a newbie. I read some decent reviews about the Merkur 1904, and ordered one. I accidentally ordered the Open Comb version. What is the technical difference?

There isn't much of a difference. You will be using the open comb like a closed/safety bar. If your angle is wrong, you will see teeth marks in the lather right away!

They should shave pretty much the same. Open comb just looks awesome, has more visual feedback about your angle and lets you shave longer beards easier