Indeed, Ducati, you are right. Practice and sparring are VERY important for martial arts. I cannot imagine a martial art without sparring. My main style is aikido and aikido is all practice, all sparring - well at least my school, where we train and don't talk
Most aikido schools are all talk and little practice but that's another matter. There are almost no bad styles but usually the best ones are the original ones. Krav maga is just a judo inspired patchwork - better train judo or ju jutsu. The thing though is that you have to find a proper school (the very school). Ju jutsu is awesome but the judo schools, due to their sports nature, have more practice. This is a two-side coin because their very sports nature takes away from their practicality - too many rules. Anyway, judo fighters are still one of the best street fighters. So choose the most suitable for you style and then find a good school. Well you will most likely be limited by what's offered in your location. Of course, there are these styles which are hardcore fighting by their very nature - like kyokushin kai karate, although I am somehow not sure in the sanity of their methods (and heads for that matter).
Btw, having a good sparring partner is invaluable! My best friend and I used to spar each evening while we were students - wrestling, kicks, punches, combat in the open, combat in a small room - we tried everything. That was a tremendous help for me.
Like many people say, martial arts are one big family and the different styles are just a different approach.
The krav maga creators are good fighters because they are judo champions. Otherwise if a judo student and a krav maga student with relatively the same experience fight, I'd bet on the judo student:)