Thank you for the reply and insight!
No reflection on your response, but definitely on the Meraki product, is that SNR and RSSI are very different things and we need to know both to make certain determinations about how our clients are performing, and why. Yes, SNR is a better judgement of how well it's going to communicate, but not at all useful for determining its likely "RF distance" from two access points (and thus whether another AP is needed between)...you must remove the relative noise factor to get an absolute measurement.
/Rant mode on...
As for having to subtract 95 from what is apparently, then, a quasi-arbitrary number, I'm not sure why they don't present the signal in terms of, say, types of fruit. If I need to do math or cross-reference a table to find the information I need, they could just tell me the signal is "mango", and I can go look that up. Wasn't this stuff developed by a group from MIT? What this tells me is that the product is suited for only very small, very simple environments with no RF challenges, and I should just shut up and drink the wireless they give me. Yep, I could call, but what kind of business model encourages customers to occupy expensive (to Meraki) TAC time? I know, gotta keep the GUI simple for the cloud management customer base, but a few "advanced" tabs would do wonders. "I'm sorry, customer, but the product you purchased does not supply ample information for me to diagnose the problem." /Rant mode off.