Flying to Rome was my first experience with Ryan Air. Ryan Air is typically the butt of jokes because of it's ala carte menu of services and no frills approach to flying. Anyone who had flown in the United States since the time when speculators drove oil prices up to nearly $150 a barrel, is well used to ala carte services from their airlines. You will pay to book luggage, pre-board, have a Coke and recently they've even added pay toilets (1 euro) for one hour or less flights. The good news is, however, the flights are cheap. Dirt cheap in some instances. I have heard of instances of 20sek fares. (approximately $2.50)
That said, I thought it was a great value. Four of us flew to Rome for about $600, which is actually pricey where Ryan airfare is considered. The plane was new. I've flown some transcontinental flights with Delta on planes that looked like they were being held together with dental floss and electric tape. The seats were cramped but no more so than any standard domestic class flight, really.
Additionally, it is about 90 miles outside of Stockholm in a little city called Nyköping. They make it easy to get there. Busses leave central station all day at regular intervals. I actually liked the opportunity to drive through the calm and scenic Swedish countryside. Something I rarely get the chance to do. Farms and gentle rolling slopes covered in snow dot the countryside.
Most of the complaints regarding Ryan air come from the fees. If a flight is advertised as 5sek, some get irate to see it turn to 150sek with fees for internet booking, luggage, etc. Again further proof that some people really do just expect something for nothing. I am firm believer that most times, you get what you pay for. Then it is up to you to weigh your priorities.
All things considered, it's still a great value for inexpensive travel. Even with the fees you are likely to pay double or triple with SAS or other large commercial airlines. For a quick long weekend trip and a short flight Ryan air does the job quite nicely.