I recently flew Sterling Air from Berlin to Copenhagen, my first experience with a European discount airline. The B-737 flight was on time and the level of service was good, though minimal. The ticket price was very fair--I think I paid 42 Euros one-way (SAS was asking about 100 Euros for the same flight).

However, I was surprised to find when I checked in that Sterling has a weight limit of 15 kilos for checked bags and they allow only 1 checked bag per customer. My one bag, because I was on a 2-week trip to Europe and I needed a diverse wardrobe, weighed about 21 kilos (which is under the standard limit for international flights). The charge for my "overweight" bag was about 40 Euros, payable in cash only on the spot. Luckily, I had the cash and I paid it and had no problem.

But I guess I learned a lesson, which is to read the fine print when it comes to flying discount airlines in Europe. The Sterling baggage policies are clearly spelled out on their website in the FAQ section.

It just never occurred to me that they would have different baggage limits than the standard ones that I'm used to. So, lesson learned.