Incremental improvements
For those considering QR, there have been incremental yet significant improvements to pay/living/working conditions over the last year. As with any airline, this is not a rose garden, but things are definitely greener.
From a personal perspective, QR is a reasonable place to work, living in Qatar can be a challenge, benefits are adequate. There are individual events which inspire much rhetoric on these bulletin boards but though they may be unfair, they are also infrequent. Possibly management here is learning and more importantly, maturing.
IF you are willing to take the risk of evolving your pilot career on the short track, this is likely the best place IF you can keep your head down, make a bit of noise occasionally, and stay focused on operations (at least for F/Os). That doesn't mean that fate and chance might randomly seek you out to the detriment of your career. It may also mean you could be a 30 year old B777 Captain and honestly, how many places in the world could THAT happen?
DECs have different objectives. This is a stable and reliable airline if you are willing to suffer the occasional "spanking". Simulator sessions are reasonable as are most of the line check pilots (there ARE exceptions). Rosters can be somewhat onerous on certain fleets compared to legacy European and North American carriers but if one does not enjoy the profession of flying this is likely the wrong place to work. Destinations are varied and interesting and with a few exceptions (again) layover facilities are adequate (though more and more moving toward the airport rather than downtown).
It is distressing to read the threads from Emirates pilots and I am not sure why such a prestigious airline is allowing their pilot workplace to deteriorate so seriously. Possibly only the voices of a few disgruntled individuals are being heard but personally, I am currently quite happy to be employed flying with QR.