As a hearer, I prefer when sermons tie everything together. I'm not picky about whether the main text for the sermon is the Gospel or one of the other texts for the day - but there's a reason those particular texts are chosen for that day, a common thread for every one of them. I like to hear how that provides some insight into the Gospel. I also like to hear Salvation's Achievement and Salvation's Delivery in there somewhere too. And Law and Gospel, of course.

Is that a lot to expect/ask for? Maybe. But I'm an idealist that way.