I traded in an office for the past 3 or so years just recently began trading at home. Traded first in an office w/ about 30 traders, then a smaller office w/ 3 other guys.
Depends on the traders. If its a smaller office w/ good traders, healthy competition and a lot of informative talk, it can be very helpful, as long as people are quiet during busy times. I think if you're a beginner, i.e. two years or less of expirience, you should be around peers.
You have to be more mature and confident to be by yourself. You have to have a solid routine and be very disciplined, able to be VERY objective about your trading, the market environment, and what opportunity is available. Able to know when to take breaks and when to focus intently on the market.
Hope this helps.