Pilotti is good choice for sleepover before or after flight. Hotelli has nice staff, restaurant is ok enough for light dinner if needes, early breakfast and possibility to have take away coffee with you is almost priceless for those who takes early flights. Rooms are small but confortable enough, bathrooms are cruise-ship type, really small, but but ok. Hotel has minibus service to/from Airport of Helsinki Vantaa and as well good bus connections. Next to hotel is one of the biggest shopping centers in the area.
For me this hotel is perfect sleep over place, usually before early flights.