My recommendation is to go back to PoA for now, but when Chainmail 4 comes out, give it a week or two to test out and see if it's ready for primetime.
I did have a lot more success with Chainmail 2 and 3 than with PoA at all, but that's mostly because I came in at the tail end of PoA and people seem to have much higher level characters than my little Level 3. I can appreciate the value of having some kind of motivation to do stuff that's lacking in Chainmail yet. On the other hand, you'll have to consider replay value for PoA also.
I did have a lot more success with Chainmail 2 and 3 than with PoA at all, but that's mostly because I came in at the tail end of PoA and people seem to have much higher level characters than my little Level 3. I can appreciate the value of having some kind of motivation to do stuff that's lacking in Chainmail yet. On the other hand, you'll have to consider replay value for PoA also.