I have to confess... I'm mostly a Reaper-Guy... nevertheless I tried out and finally bought Bitwig since the Ideas I came up on it were pretty nice and the workflow is so damn well thought out.
There are things I would love to see added (such as retrospective Midi and Audio Record) but over all it is a very rare sight in this industry.
You buy the thing... and you get with it all that you'll ever need.
there is no "Cool you bought our Pro-Software... but really you want to get this other bundle of us and that Library"
Bitwig is Bitwig... is Bitwig... and I really hope they don't forget that like one year ago, where they tried to release a seperate bundle...
I would however recommend you also get a good Midi-Controller with it (if you don't already have one)
I strongly recommend a Launchpad or other Controllers, that are supported by the DrivenByMoss Scripts (Awesome scripts for Bitwig and Reaper to really enhance the supported controllers - adding Step-Sequencing-Style Note Editing O.o , Velocity Sensitive Fader Controlling, and soo much more for no additional cost ... other than the Controller)