I should probably say more than just yes. As Matthewdupreez mentioned, the actual time on your part with 3D printing is less than with foam (unless you design your own, but that is a whole other story). 3D printing also gets much more precise contours and gives you far better control of your geometry than foam. There are some amazing foam board designs out there, but with 3D printing it's pretty easy to achieve results that are more detailed than most RTF designs. Then on top of that, 3D printed geometry is thinner than foam, so you can fit more into the same size of structure (especially important with thin sections like wings). Finally, many would disagree with me on this, but 3D printed planes fly better than foam board planes in my opinion. They just feel a little more polished and a lot more precise in the air.
On the downside, as you say, they take longer to repair and are more fragile. But if you crash an RTF plane, you're waiting at least a week for parts and are paying a lot more. They weigh more as a whole (except for whatever black magic Eclipson uses). But they aren't that heavy, and they still can fly very light and floaty with the right setup, even using normal PLA, and the added weight helps with the wind (I personally like heavy planes too). And they cost more than foam board, in the US at least, but they are still quite cheap compared to the cost of the electronics. So overall, I would say very much worth it.
