What do I do with my miles? I let airlines cheat me by not always crediting me flights then I let the airlines change the rules so that my miles become worth less!

Seriously, I redeem them for coach seats domestically and occasionally, internationally. I don't upgrade on them. If the airlines are curious, they don't lose any money on them because I usually end up redeeming awards on tickets that are cheap anyway. When the tickets are expensive, they never seem to have seats.