"you can only use certain faucets based on the acidity of the RO water" it is not the acidity so much as just the cleanliness. RO water is aggressive at dissolving anything it can, despite having a 7.0 pH in many cases. Otherwise it would taste like lemonade (low pH) or bitter (high pH).

Code or not, I would not want to have any kind of faucet without some kind of drain. Wouldn't have to be a full fledged sink but just in case someone left it on... or didn't hold the glass just right under it... or it leaked... or whatever, I'd want somewhere for that excess liquid to go other than on my counter, and subsequently my floor. And yes, I know potfillers don't have a drain either. I'm not much of a fan of those either for that reason and others.

I've had the hot/cold dispenser before (now I just have hot) and they are very nice to have. Whether or not you find it useful for hands I can't say. I just would want to be sure I was paying attention before putting my hand under that spout! But it's one of my favorite kitchen thingies. Mine was/is set up much like John's and as you can see, getting a second person in there will be a little tight, but doable.

iLoveRed, no worries. I think I found the answer. I definitely need an RO faucet that supports an air gap feature. This Delta faucet can be either. "If you have an under the sink RO system you need to have an air gap. If your RO is located elsewhere you do not. Good reference here." from: http://www.water-softeners-filters.com/air-gap-info  “This is the most common scenario where an air gap faucet is recommended, and here is why: For technical reasons beyond the scope of this article, it is possible to create a vacuum in the discharge line of a reverse osmosis system connected to the sink drain. If for some reason, the sink drain happened to be filled with water up to the point at which the RO discharges into the drain, contaminated water from the sink drain could be drawn into the discharge side of the RO system. The solution to this possible condition is to install an air gap in the RO discharge line. If there is an air gap in the discharge line, and a vacuum is created on the discharge line, a small amount of air (rather than contaminated water) would be pulled back into the drain line. This air would be almost immediately purged when the vacuum was relieved back to the air gap, with no ill consequences.”