Poor
That sucks!
Less than 5x initial bet is poor. I have had spells where a dozen RTG bonus rounds have come in at under 10x bet. I get the feeling RTG bonus rounds pay less than the average MG bonus round. Worse, RTG have a 2000x stake cap if you ever get a really good bonus round (worked out at 40,000x line bet, sounds better that way).
Operators have claimed that their own RTG casinos are paying 96%+ on the slots, slightly more than MG, which averages at just over 95%
It must be that the distribution of wins is different with RTG slots, with a higher amount paid outside of the feature rounds than at MG.
The only consolation is that RTG gives out more bonuses than MG, so provided you can decipher the bonus terms, you should get a decent amount of play. Pretty much all RTG slots have a progressive jackpot (called the Random Jackpot). I suspect that the contribution rate can be changed at will by the operator as I play one RTG where the RJ hardly moves from day to day, and is barely over 1000 on most slots, and at another the RJ is often around 4K to 6K on most slots, and increases visibly as I spin. Possibly, RTG casinos where the RJ barely changes and stays low pay out more of the "96%" on the basic game, and less from the RJ being hit.