This is perfect if you are looking for imperfect sounds. The focus of Cassamplerette is not accuracy, but of regular sounds that are, in my opinion, recorded wrong or long ago by your uncle Earl drinking whiskey at 2 in the morning and trying to record his ideas. In that context this works out, atleast for me...mostly because I don't like everything to sound super clean all of the time.
There are not a lot of controls to manipulate, but the ones that are there change the sound deeply (Reverb, Delay, Hi Damp, Low Damp, Wonkiness, Noise, Amp/Cabinet, Saturation controls). It could probably benefit more with a compressor on the performance view, though. With 2 channels of 40 or so instruments that you can blend, you can definitely get some great nostalgia working. I use Cassamplerette as more of a backing instrument for my more cleaner sounds that don't have a lot of "analog" depth.
My suggestion with a library like this is that one should go through each of the instruments individually and pick what you would like. Usually in Kontakt libraries you are after preset inspiration. This comes as two presets (instruments & drums), so it is meant to be explored versus exploited. The reverbs they added are usually just right for the sounds that are accompanied. The drum version has 8 pads with multiple basic controls & MIDI learn, so it is great for many types of uses. Don't expect fully sampled round-robin BFD/Addictive Drums type of drum kits, the caveat of the Cassampelrette drums is for those nasty drumloops that fill up clean space.
Because Cassampelrette is so contained, however, you will need a fast computer and lots of RAM to run it efficiently. The main instrument take about a good minute to load on my computer with i7 processor & 12GBs of RAM, but ti's worth the wait. This is not your regular Kontakt library where you zoom through the presets & judge how the instruments are from there. Take your time with it and it can definitely be rewarding if you are looking to add some instant grit into your productions.