The only annoying part of contacts for me is the cost of paper. I do 35mm and 120, and each roll costs me an 8x10 proof, about 60 cents.
I don't use them to judge of sharpness and exposure. After all, my lenses are plenty sharp, and I've known how to meter for quite a while now. Most of my negatives are usually correctly exposed, and in focus. I seldom need to bracket, even with slides.
But I find them very useful to evaluate which pictures to print, and as a record of my work. I don't have the time to print everything, let alone everything that I want to print, so having a contact always allows me to see if what I shot makes pictorial sense.
In B&W, I use only a few films, and try to be as consistent as possible. I eventually invested some 40$ in a PrintFile proofer. That way, setting up for contacts takes 2 secs, and I can expose all my negatives within a few minutes. I batch develop, exposing a negative while the previous one is in the developer tray. Then it's all shuffle in stop bath and fixer. A dozen negatives would take less than 20 mins.
Now, if you're talking about RA4 contact sheets, then I'll agree they're a royal pain in the neck...