Do you mean Delta Premium Select or Delta One or Delta Comfort?
My experience with Premium Select on Delta wasn't great if traveling alone. The seat in front of you recline significantly to the point that it is hard to get in and out of the seat with the hard armrest. I haven't flown Virgin so can't comment on that.
I know some people dislike bulkhead seats but that has been my go-to on Delta Comfort if I can manage to get it, which gives me enough leg space. I'm fine keeping my backpack up for take-off and landing, and keep a small purse/bag with me during take-off and landing.
Now Delta One is a complete different story, if you can afford it, that's the way to travel.
My only experience with SAS is economy within Europe.