I've played this slot to death over the last couple of years. I've gone through periods of doing the math, following the rtp, varying the stakes, doing a rain dance, all of it.
The first requirement to playing DOA in my view is the right mindset in terms of the entertainment factor. The base game is certainly not everyone's cup of tea, some will declare it outright boring, if you're looking for all singing all dancing slot activity, this won't appeal.
The second requirement is easy in the first part, the expectation of the potential of the bonus round - after countless bonus rounds, I still feel a tingle when it triggers that this could be the big round of thousands x stake. The second part is harder to achieve - the ability to shrug off countless bonus rounds of little to no value. If these rounds make your hackles rise, then this game really isn't for you.
With all that said, I've experienced the frustration of 100's of bonus rounds with little or no value and convinced myself I'm due that big round.
These days, and I have to say it's taken all this experience to get to this point, I can shrug off an individual losing session or an extended period of months of losing sessions with no great return easily. I understand the game for what it is, and how remote the big pays are on it.
It will still remain one of my firm favourites.