Just finished it. I liked it the first time I read it and I still like it now. I was surprised at how closely the movies followed the book. It doesn't have quite as much drama in some parts as the movies, nor are the supporting characters as well defined, but Mr Hornblower is earnest and geeky, and he does have some cute, slightly snarky, and happy-go-lucky friends on the Indy. The biggest difference was the prison chapter, of course. Horatio had more prison roommates in the book, but apparently little cameraderie, no oubliette, and absolutely no carrying beautifully tragic best friends in the rain. Also no breaking the rules of war, and no annoyingly smug comments from Horatio about how he's going to get them all out of there. (Midshipman Hunter is a lot nicer in the book too, but we don't hear from him again after they are captured. Too bad.) The cuddle reflex here is all for poor lonely honorable Horatio. He reminds me a lot of Book!Sharpe, actually, which is unsurprising considering that Richard Sharpe was meant to be a bit like Hornblower-on-land.
Also, the Duchess here is already wearing an empire waist dress, which surprised me. In the movies I didn't think they were in fashion yet. I wonder which is right? Horatio was born in 1776, plus he was nineteen (maybe and a half) when he was captured, so...1795? It seems he was captured while the Battle of St Vincent was going on within earshot. When did empire waists come in? I could look this up, but maybe someone will just tell me! :D
Anyway, a good read, and more fun and comprehensible after reading a steady diet of AoS over the last two years!