There is a certain push-and-pull, there are advantages and disadvantages to being alone, as well as to being in a group. I have historically operated alone but now I think that it’s the team effort that has to be applied to solve any significant task.
First of all: why do I think that working alone is efficient? Alan Weiss says, do not form a group unless it increases your productivity ten-fold. The cost of communication and management means that if two people produce 200% (where 100% = one person’s output) of work – then you’re operating at a loss, and each individual should just operate independently. If on the other hand the output of a two-person team is 500%, then it makes sense. I find that solo operations are actually very, very difficult. You lose focus and discipline right away, and you have to discover best practices yourself – these are some difficulties.
If you’re working in a duo, accomplishments by one person can be transfered to the other very quickly, thus saving the latter the research time. If my partner discovers a best practice and just transfers that knowledge to me, I feel that I’m saving time by not doing the heavy lifting myself.