Empire: Total War is, without a doubt, the worst Total War game made. That, of course, doesn't mean it isn't good.
Now the main reason I think this still isnt as good as previous titles is because the real time land combat, truely the heart of the total war series, has just been overly simplified. This isnt historically inacurrate. Over the course of time, man has become more and more reliant on the machine to wage war for him. Furthermore, in the real 18th century, British tactics were nothing more than firing at regular intervals and then fixing bayonets and charging when the enemy was close enough. This is reflected in the game in that, thats all you have to do! The globe is huge on this game but from one corner to the other, combat is the same: guns, guns, and more guns. I just laugh at how previous Total war games drilled it into your head that numbers dont win a battle but in this game, they pretty much do.
Bottom line is that if you're a real fan of this era Id highly recommend this game, but if you prefer more strategic depth to your combat, it might be better to stick with Rome or Medieval II