I've flown with them several times, never paying more than a pittance plus taxes for the privilege of being flown thousands of miles, so I can't complain really.
I would never describe a Riot Air flight as being fun. Conditions are spartan and the Riot-Air experience, from the long queues at check-in, to the scrum at boarding time, to the non-reclining seats with no legroom, to the staff constantly trying to flog you stuff you don't want, can sometimes border on the hellish.
However, once you're at your destination, you have the satisfaction of knowing you've got somewhere you'd probably have never even thought of visiting for next to nothing.
Tips for flying with Riot Air:
1) Take only hand luggage. They allow you up to 10kg. I have toured around India for several weeks with less luggage than that! If you're going somewhere cold, so need to take more clothes, wear your heaviest layers of clothing until you check in and clear security. That way you can stretch your hand luggage allowance even further!
2) Eat and drink before you fly, so you don't need to buy anything on board the aircraft.
3) If you make a lot of trips abroad, buy an annual travel insurance policy elsewhere, not the individual policy offered by the airline at the time of booking.
4) Expect low standards of customer service and hard landings. That way, your experience will not come as a shock.
5) If your journey is for business purposes, tell your boss not to be such a cheapskate, and put you on either a proper airline or even a train instead!
At best, Riot Air is probably the nearest you will ever come to getting something for nothing, but I doubt I would ever choose them if I had a choice and they were charging anything like a normal fare.