i've tried Drum Replacer a couple times, but with results that didn't make sense.
Patch Points is a feature i have not used yet, why? i don't know. what are they again?
i never use the Step Sequencer, or the Matrix View (maybe because i do a lot of my MIDI stuff in Maschine standalone, and bounce all the individual audio tracks from there into Sonar).
i never use Take Lanes because i've had a couple experiences early on with them where my audio would disappear (even though the visual representation of the audio was on the screen still). so i use my own way of comping in Sonar with individual audio tracks & that works well for me.
i have yet to use Addictive Drums, Lounge Lizard, Studio Instruments, Strum Session, and a lot of the Blue FX stuff.
what i do use, though, i pretty much LOVE.