We just ran a survey ourselves. Keep in mind, it only has 84 respondents and is in no way statistically significant! Nearly all respondents were US based.

Of users with intermediate to advanced design skills, MakerBots held 30% of the market.

Of users with no design skill, or beginner level design skill, MakerBots were quite a bit below Solidoodle, Printrbot, and RepRap.

People with more experience are buying the more expensive machines, and people with less experience are going for cheaper machines.

Drew Taylor
https://3Dagogo.com