Two years ago, Fool contributor Brian Stoffel wanted to choose one 3-D printing stock for his growth portfolio. He chose Stratasys (NASDAQ:SSYS). Even though Stratasys stock has underperformed rival 3D Systems (NYSE:DDD) since then, Stoffel still thinks he made the right decision.

In the following video, watch as Brian explains what Stratasys' recent mergers mean for investors, and why he's thinking about buying shares of the company for his real-life Roth IRA.