I have used both SQS and PG-based queues and for the smaller workloads/smaller systems (read: "not very very large systems") I now prefer the latter. There is also a non-trivial amount of stuff that we turned out to need for operating SQS at scale on the application side, basically to compensate for the things SQS does not have. It is great it doesn't have those things, but if you have a smaller application you might want to have those things instead and sacrifice a bit of scalability.
The advantage being that you could sort things to implement priorities and such? Did you use listen()/notify() at all?
ETA: seeing your list of missing features now, that all makes a lot of sense. In my mind the biggest advantage of SQS is that it glues together all the other AWS offerings, so you can go AWS -> Lambda for an instant job queue (with concurrency limits, etc. so you don't blow your hand off - perhaps undermining the simplicity argument). But everything you're saying makes sense if your job queue needs any degree of sophistication.
