Here are two disadvantages that seem real to me: (1) Turn-around time. If you need a small feature developed and it's going to take a full-time developer 3 wee

Here are two disadvantages that seem real to me: (1) Turn-around time. If you need a small feature developed and it's going to take a full-time developer 3 weeks from start to finish, how long will it take a developer who works half time? 6 weeks. (2) Team scalability. A lot of people prefer smaller teams of developers because large teams don't seem to scale well. (A team of 10 people usually isn't twice as productive as a team of 5. At least, this is a pretty common view.) If your team has part-time employees, then it will need to have more employees to handle a given workload.