I've only recently discovered XRB and I'm about half way through digesting the whitepaper. This sounds technically better then IOTA, yet has flown under the radar all this time. Is there a specific reason it's so undervalued? Any significant downside I'm missing from the white paper? I'm close to a buy decision and I'd like a critical view on it.

Also, is Mercatox the only exchange I can buy on?