If it helps any, the time it takes to read is inversely proportional to how good it is. The 100k word stuff I’ve ripped through in a couple of hours is the stuff that sticks with me.
Yes, this.
If it's that good, that well written, I basically devour the book. maybe not in two hours anymore (that was in my 30s) but if I finish it in a couple days or a week, you know I'm buying it, shelving it, and referring it to everyone.