Wow. 5,000 spins on Aloha! without a bonus would be gobsmackingly unlucky (approaching hundred-thousand-to-one unlucky, I'd expect). Did you mean 500? That would be very bad, but less surprising - the free spins are pretty rare considering there's six reels with five spaces each and you only need half the symbol visible to trigger the bonus. I've had them about once every 100 spins on average. I quite like Aloha!, actually, but I agree the variance is very high. The best single hit I've managed was 23 of the red faces in the respin feature, which plays about 400x I think, and 100x bonus games don't seem that uncommon. So I'm in fairly healthy profit, although I doubt it would last if I went back to it.
Presumably the 36,000x top payout on Pyramid - outrageously unlikely as it might seem - is actually an artificial cap? After all, the rules as written mean Pyramid can theoretically keep paying out forever. If you got a bank of identical symbols in the middle reels, below the wilds, and never matched them AND managed to get a line of three wilds on the top, it could keep giving you wilds forever, which would automatically match whatever symbols dropped onto reel one and then get replaced. It happened to me once, but I matched my main symbols after about 10 hits. Of course the payout was enormous, about 800x, but then it broke the run. I haven't really played it since. I figure I got my one lucky shot at it, and ended up breaking even, so I should call it quits. I prefer slots with more features anyway...
I didn't realise Big Bad Wolf had a similar cap of 2,000 symbol drops or something like that. I got two bonus rounds in the same set of spins and was mightily pissed off when the game just stopped. But I guess any game with drops and a large number of wilds needs to do that.
I wonder if there's a limit to the number of bonus rounds/respins you can get on Invisible Man, which can also theoretically go on forever. I've had two freespin bonuses in the same set of spins a few times, one of which went on for about 20 minutes and paid about 500x. It seems to only let you trigger the Police Spins or Invisible Man Picks once for any given bet (the meters reset but don't fill on subsequent bonuses), but there's no indication that you couldn't keep getting regular bonuses forever. I'm on a bit of an Invisible Man kick at the moment - won £5000 on it today! It's my favourite NetENT slot at the moment, until it inevitably turns on me...
There seems to be a generally anti-NetENT feeling on the forum, but I've found them to pay out a lot better on average than any other company's games. Obviously that's part of the variance of playing slots, but perhaps I've been extremely lucky rather than just quite lucky, like I thought?