I've read many of the posts about RyanAir in this forum. It appears the main pitfalls are:
1. Forgetting or losing your home-printed boarding pass: about $100
2. Hand luggage exceeding 10.00 kg or not fitting into the 55x40x20 cm sizing box: about $60
3. Neglecting to get the visa stamp outside security or forgetting travel documents
4. Arriving at the gate too late (due to item 3 or any other reason): purchase of a new trip
5. Checking luggage too heavy or too late for cutoff
I have flown Ryanair twice (FEZ-MRS in 2008 and OPO-FAO in 2012).
1. No issue in 2012. Printed boarding pass a week before flight.
2. No issue as we checked our larger bags. No one was checking that closely at OPO but most people that had rollaboards were using small ones you don't see very often in the USA, like this "approved" one:
http://www.ryanair.com/en/news/ryana...d-carry-on-bag.
3. At OPO check-in agent forgot to stamp documents, and we were sent back from security. No line when we went back to agent (although this was a domestic flight, so probably not a lot of people checking bagge/non-EU citizens).
4. Not an issue for me, although both departure airports were pretty empty when I was there
5. No issue. In 2012 we purchased the 20kg option, which combined with the 10kg hand baggage was plenty for us for a two week trip.