I think front-only works well. I like it better than rear-only. My commuting setup consists of a handlebar bag and a single front panier. I could tell sometimes at first that the steering was a little off with the bike loaded on one side. But then I quickly learned to compensate so I don't even notice it now. On my bike at least (Surly LHDT) concern for balance in the front is not something to worry about.