You know I have Studio Drummer and Kontakt 5 but never bought Komplete . Always wondered if I would really use Battery since I don't fool with electronic music. I added a few decent pianos to Kontakt so for me I'm not sure I would really use all of it. 

 Have you made much use of Battery?

Good Lord!!!!!!!!  After a 6 hour Install, the Serial Number won't Activate... GRRRRRRRRRRRRR!!!

Starise-  Yes, I love Battery.  It is aimed at electronica, but there are some VERY good drum kits in there.  I can't imagine not being able to find a drum sound you were looking for in it.  I have hardly scratched the surface with it, but it has some very good F/X and wave editing features as well as a step sequencer, and you can load just about any type sound file you have into into it.

I am also very impressed with The Giant Piano.

 Wow...if Komplete had a built in DAW you probably wouldn't need anything else.....but we have Sonar for that.

OK... got it all working. 
The Giant is AWESOME... I highly recommend it.  Very versatile piano.
Session Drummer has one of the best sounding acoustic kits I've heard.  Now I need to lean how to use it.  LOL
Battery 4 is very interesting and has some very cool kits in it geared for electronica, but it has about a million sounds in it.
I haven't really tried out Session Strings much, but it might have some potential.
I haven't listened to Monark yet.

I guess I have been Kompleted.  LOL

I made a mistake above...... there is no step sequencer In Battery.  Oops.  Sorry.
Battery 4 sounds great!

- insert envious post here -