I recently crossgraded from the full version of Kontakt (which I no longer want to be without) to Komplete Ultimate10. Something to realize about instruments in this package, especially Kontakt and Reaktor, is that they are also stronly-supported and flexible platforms for third-party samples, instruments and soundware. I haven't explored Studio Drummer yet but, by virtue of packages available for Kontakt, I have percussion packages by Steve Gadd, Bill Bruford, etc.; also cinematic, orchestral, ethnic, found-instrument, electronic, artist and tuned-percussion instruments and libraries, single-shot or phrased. Kontakt itself has the ability to construct your own drum/percussion kits from any samples or loops you want to use. When you investigate the depth, breath, and capabilities of the NI instruments you realize that they are mind-boggling. NI is not alone in providing deep-editing and capabilities to quality instruments, but they are experienced and they definitely don't ignore their customers or the after-market. I don't think that Komplete will ultimately limit your percussion needs---I'd wager that the exact opposite would be true.
This doesn't even get into the synths provided like Massive (aptly named), Absynth, and FM8 that consistently get good reviews and are ranked well in user polls, and top-flight virtual instruments and orchestral/band libraries, and the processing plugins. I'm sold on NI stuff. I think SampleTank/IK (which I have) is moving up, but, for my needs, Komplete is the stuff. I also love AIRtech stuff (could completely go desert island with the AEIP+), UVI (nice sound and performance libraries), Artuia (exceptional synth emulations/implementations), instruments by Cakewalk, IZotope, WAVES, etc., and a lot of vendors I haven't mentioned for VI's. I use what I like, so I'm not exclusive to NI but I think Komplete (esp. Ultimate) is the most comprehensive and flexible platform available, and at a reasonable (I would actually say bargain) price to boot.*
That being said, I do have BFD, EZDrummer, SSD, Strike, among others, and I enjoy using them and exploring them. For me, it comes down to a work-flow v. inspiration v. exploration v. mood thing.
I love this 21st century---a great time to be alive.
Paj
8^)
* My path to Komplete Ultimate 10 was: Initial purchase of Komplete Element on a daily sale for $19; email upgrade offer from NI for the full version Kontact5 for $79; on-sale crossgrade from Kontakt5 to Komplete Ultimate 10 for $399. So, due to NI's consideration for previously registered purchasers, I was able to get Ultimate for $500 (half-price). That's Less than $7 per instrument, library or plugin.