I stopped paying for F after the AS/VX merger. I paid for one flight in AS F, and then never again. Before that I had not flown econony in years. But AS F is simply not worth paying for. It's not just the seats, it's the complete lack of service and lack of caring. F is treated the same as Y. There is no effort made to provide premium service.
I've now status matched to UA so I have a real option for F on long flights. I still take AS (and pay for economy) on routes with no premium F available, for the mileage earning -- if they fly where I want to go, which is getting rarer and rarer as they kill old VX routes out of SFO.
The only redeeming quality for AS right now is the FFP (which is by far the best out of the US carriers) Other than that it's an inferior product with an inferior network. Basically they are just a piggy bank to store miles earned from international partner flights. Actually flying them is more or less unnecessary.