I'm currently up to mission 9 and before starting this campaign I had less than 2 hours time logged in the F15 (according to the logbook its probably slight more than that as the logbook isn't on my 1st pilot) and most of that was messing around, not really combat. I've had a little bit of learning to do consequently.
As the campaign has progressed the difficulty has escalated and you get more tasks to do per mission. Most of your engagements tend to be BVR however I have got a couple of guns kills during the campaign, not really had any proper close in dogfights vs other fighters they tend to be over one way or the other way before the merge.
So far I'm really enjoying the campaign and it has actually given me a reason to play the F15 properly and the story driven aspect of it makes some of the missions more interesting than they would be otherwise.