I can honestly say the departures experience has always been very good for me. Check in queues are almost non existent and security is very efficient. I am usually in the departure lounge less than 10 minutes after arriving at the airport, regardless of season or time of day. I once arrived for a flight to Heathrow about 40 minutes before the stated departure time. I got out of the car, walked though security, through the gate and straight onto my seat in the plane. I wouldn't recommend doing that - obviously - but the speed of the process is probably the quickest of the airports I have flown from in this country. I have always maintained that, even though the gates system is flawed and a little confusing, LBA departures is actually very good.
Arrivals on the other hand....
My advice, if you want things to feel as uncrowded and relaxed as possible, would be to take coffee and a muffin at the café next to Burger King as it always feels somewhat more peaceful in there and is a nice place to do a little people watching.