I think that you are perhaps you and your co-founder are the only ones who can answer this question. I know that sounds trite but that's not what I mean it to sound like. My point is this: no one knows better than you two what your goals are with the company. You said, "We're bootstrappers by nature and would rather have our first business be a strong base hit than aim for the fences." I'll take you at your word that this is true.

So the question that you and your co-founder have to answer is whether or not you want your personal finances to be at $25m, $50m or higher in 10 years? If so, it's less likely that this will happen if you bootstrap rather than raise/sell. And there is no right/correct answer - no one can tell you which you should do, only what they might do in your situation or what they think someone like you might do in that same situation.

There are other aspects to it as well but the key point is, in 5-10 years from now, what will you want? Do you still want to be running the business or will you want to have hit the "reset" button and have moved on to something else? There's no crystal ball so you have to take the risks and rewards all into account.

Good luck and congrats on getting to where you are!