You can't get married to the stack. When you've been to the rodeo a couple of times and you work with an experienced team, flaws in technologies (Ruby) will become apparent from the start and your requirements will force you to fall back on what's tried and true. Unfortunately, sexy things are often pushed aside in favor of conventions and you have to have a common sense approach towards providing a solution that solves the myriad of problems you're facing.
Locking yourself into a technology choice is a hard decision to make, but if you're living the dream and need to attract a certain kind of person to make that possible and it makes financial sense in the short term, which is what you're probably after, then you have to go with it. Rails and Node.js are a perfect fit for a low-level technology service provider, but beyond that they lack mainstream credibility and when you're dealing with recruitment issues, which hopefully you will, it's always easier to hire someone who has versatility over a guy who just does one thing.
Good luck and I hope to checking out your work some time soon.
FULL DISCLOSURE: I wrote the first job description.