If you are trying to build up a full picture of your ancestors beyond just a list of names and dates, the kirk-session records are absolutely invaluable. At least, if your ancestors were a bit naughty and got into the bad books of the minister and the elders. If they kept their noses clean you won't find out much more about them.
I started doing genealogy back in the early 1980s when you had to go and queue on the steps outside Register House in the morning before they opened up, and once I had got some elementary family-trees going for both sides of the family, I discovered the kirk-session records in the Scottish Record Office handily next-door (now the National Archives of Scotland) and was often able to put some flesh on the bones of my ancestors with their help.
I still have to pinch myself when I sit down here at the computer like this and spend my pension on Scotlandspeople credits, so easy, and so tempting! If the k-s records do become available online in my lifetime I expect I will splash out on them too.
Harry