My office is the same distance away from my bedroom as Super's. But before this I worked at an office 30 minutes away. But due to my countryside living there weren't many offices closer. I'd say base your decision on the office itself not the distance.
You and Super share the same bedroom?

My office is only about a minute and a half from my home. I love it that close too. It motivates me to go into the office and get some serious work done constantly. I am at the office everyday. Sometimes I will even pop in around midnight if I am bored and need to get some paperwork done. I could work from home like many others, however I don't feel that I would be as productive at home than I am at work. If I didn't have my own private office at work, then I probably wouldn't be there most of the time. Since I do have my own private office, I can easily shut the door and hide from any distractions.
Do not sign with a broker just because of the distance of the office though. As a rookie agent, training should be your number one priority. Interview with a few brokers before choosing. Hope this helps.