I use DA and PA every day for reporting, researching and most of the time it's a pretty good metric to compare domains and pages but recently I did an experiment and I was surprised when I saw the results.
Two months ago I "link bombed" one of my old, unused websites with thousands of spammy blog comment links. Before the attack, its DA was 21 with a few hundred links.
In August, after the recent OSE update I checked the website again and I was quite surprised to see DA 61 as a results of 8340 links.
A DA value over 60 is considered pretty strong and it's interesting to see that spammy blog comment links could change it so significantly. Someone who doesn't know the history of the domain might get interested in advertising on such websites because the mozbar shows a high DA value.
I know it's difficult to algorithmically differentiate between spammy and valuable blogs but a future OSE update could focus on this issue.
Let me know what you think.