I use real butter most of the time but use it very sparingly. I just scrape the butter so I don't use much.
Recently, though, someone gave me some squeezable Parkay. I used it on some veggies and still have half a bottle left. It was good tasting. I haven't thought much about switching since I use so little butter. It lasts me a long time. One stick of butter must last me well over a month, and I'm not really sure how long but a long time IMO.