Everything went smoothly, but when I have read their contract, I've found they are agree to pay no more than $8 per kilo (about two pounds) in case your luggage get lost. And the food ("Enjoy your meal") is a junk.
"Group" tickets: The price of the tickets for lowcost flights increases with the number of tickets sold. So it may happen that there is only one ticket left at the lowest price (e.g. 30Euro) and that the others cost more (e.g. 40Euro). If you buy two tickets, you will be paying the higher price multiplied by the number of passengers (in our case 40*2=80Euro, instead of 30+40=70Euro). Always check that the total price for the group is not higher than the initial price per person multiplied by the number of people in your group.