Well in a nut shell they are a set of rules that provide a basic framework that you can add to. So to someone like me with the IQ of a tree they are great, as I don't leave the room at the end of a gaming session with a massive headache from working my brain to hard.
They are card driven which I like, the mechanics for morale, movement, shooting and melee are very easy to learn, and the book is full of add ons such as extra rules for characters and artillery that allow you to personalise each game.
You also don't need vast armies to start playing, an elite force in a 4point game would muster about 20 figures and at the other end of the morale scale a raw force, about 50 figures.
There is a very VERY simple points system, but you don't have to stick to it. For example next week I hope to put on a Sikh War game with an attacking force of Brits which amount to 14 points and a defending force of Sikhs that amount to 9 points, its entirely up to you.
I've heard people call these rules Sharpe Practice lite, personally I would take that as a compliment

I think the price for the rules is expensive, but it is a very nice book and considering the amount of use I've had from the rules they are well worth the money IMHO.