Rolled only a few dice for a few (smaller) ships, just to get a feel for some mechanics. So I'm no experienced gamer and can only give my impression. You might find a lot more in-depth reviews by a quick web search.
If you like Lardies-style rules, this is for you. That's not because KMH uses card activation or silly names, but rather because it's pretty straight forward and not into technical minutiae. The quality of your crew is a decisive factor as it has influence on almost any action you can take or suffer (of course, Brits & Yanks get always out on top). There are a few cross-referencing tables, and the game requires a bit of bookkeeping. But that's all fairly easy to grasp and handle.
That said, there are some quirky rules, and the wording isn't always as clear as it could be – at least to me as a non-native speaker. Overall presentation is a bit dry (don't expect pretty pictures) and in parts even confusing (the numeration of paragraphs isn't used to full advantage). KMH is definitely no glossy or hard 'n' fast wargame but rather a very decent set of rules for casual gameplay with a fair bit of historical (novel) flavour. I'd say for only 7 quids you can't go that wrong.