About two years ago I had a flight with Vueling from SPU to TXL with a connection in FCO. When I arrived in TXL I, along with one or two other passengers, never got our luggage. I was without it for about two days but in TXL I believe it was a company contracted through their airport that was in charge (not Vueling). Side note, Vueling or just about any other airline contracts luggage handling out, so although it's quick to point the finger at Vueling, it is in reality the contractor that's to blame. I initially thought the issue with my missing luggage had to do with the construction going on at FCO (being that I had to transfer terminals). I'm so glad I got my luggage back because I had happened to pack some expensive gifts in there and I can honestly say I was not a happy camper the first two days I was in Berlin. Vueling offered my a daily compensation but I didn't really need to purchase much and I didn't want to deal with the hassle of sending receipts to Spain from the US. Wasn't worth it in my opinion.
On another note, I happened to purchase a flight with them for an upcoming trip between BCN and Palma, Mallorca. I never even knew about how bad this airline's reputation was until I saw this post on the RS forum. I then searched multiple review websites and came to the conclusion that I better find another alternative before the same thing happens to me again (even though it's a direct 45 minute flight). I didn't want to spend the extra money, but then a sort of miracle fell on my lap. I got an email from Vueling saying that one of the flight legs had to be rescheduled (they bumped me to an earlier flight time). What was great about this was that I was given the option of changing the flight to a different day or cancel it altogether (only the one flight leg, not the whole flight). I went with my instinct and asked for a refund, which I received a few days later (despite many reviews that say people never get compensated; maybe I got really lucky). I opted to just buy another flight with Air Europa, which has a slightly better reputation. I can deal with potential flight delays, but I will be one sour person if you lose my luggage.