Children pick up on atmosphere. So if you are both seething but have to wait to have the row until they are in bed, your kids aren't going to be in happy ignorance of the emotions around them - they will realise something is wrong. Better to have a row (within limits) and make up than leave them on tenterhooks all the time, IMO.
However, my parents had vicious, evil rows in front of us - the sort where you verbally throw everything you can possibly think of at the other person, dragging up history etc. etc. They would be so involved in this they wouldn't even notice me and my sister running from one to the other saying 'stop, stop'. I vividly recall this and it is horrible. They ended up getting divorced, which was awful for us at the time, but in the long run was far better than being subjected to more of these destructive rows.
If you set some ground rules, about keeping it within certain limits, I'd say the occasional row isn't the end of the earth, as long as they see you make up too. But only if you can keep it relatively civilised, not like my parents. I'd rather have an honest but not destructive row than parents who bitch at each other all the time and make snide remarks, like my in-laws used to. Dh used to avoid all conflict, as a result, didn't know how to have a row, just used to walk away from me, which used to drive me MAD. Had to teach him how to have a decent row!