seriously?! I just bought one now after putting it off for years
As long as you can get them all for decent prices, I don't think there's much to regret, because if they're using any of the 3DS exclusive capabilities, you're not going to be able to reproduce the experience on any other console anyways.
I had one for the original DS and obtained ROMs for the cartridges that I owned. It was convenient to have them all in one place when traveling without having to bring a bunch of cartridges with me.