Hey Colan,
Out of all the metric to use, including Moz, Ahrefs, Majestic, etc. I stick with PA/DA.
However, I wouldn't report those to a client nor use it as a benchmark for myself, as they can be manipulated in a positive or even a negative manner.
A PA/DA can be manipulated by blasting links that Google deems irrelevant but Moz considers relevant because their algorithm isn't as sophisticated. I've only seen this happen once or twice but it still can happen.
A PA/DA can also be manipulated by people who purchase backlinks. Many backlinks now purchased are controlled solely by a third party. This third party can block the crawling of the website by the Moz crawler. Therefore, that backlink won't show up in OSE and won't be calculated in the PA/DA. Thankfully, in local it is much more rare as Local SEO's aren't incredibly sophisticated when it comes to gaming the system.
I only use PA/DA as a light measurement. Maybe to size up the difficulty of ranking in an industry/location as a whole.
I can tell you, for frame of reference, that a DA of 30+ for a local website is RARE. 99th percentile. Same for a PA of 35+ or so for the homepage. If you see a competitor like that (or even a potential client), just check their backlinks through Majestic. If they all check out, that is going to be a beast to beat more than likely (if they're a competitor) or a super easy client to work with (if, of course, a client).
Does that help?