I have it and use it always with my Cricut. In fact, I never use my Cricut without it. But when people ask me if they should get it, I always say no. But I must clarify - it depends on how tech savvy you are. There are no instructions for it. You have to be able to learn on your own. And you have to be able to be patient with it. There are soooo many design flaws in it - I've lost designs because they got corrupted. I have had to redo designs because it decided it didn't want to cut them after the previous update from the site. I've had to abandon designs because it just wouldn't cooperate anymore.
I guess it depends on what you plan on doing with it. If you want to use it as it was created - as a design program - then by no means should you get it. I think that non-IT people created it, and these non-IT people weren't even crafters, so had no idea what it would be used for. But if you want to use for basic stuff like welding and paper/cut layout - which is the only saving grace for it, then only get it if you can get a good deal on it. Which I got a fantastic deal on it a while ago - the only reason I bought it.
And an FYI: they will be coming out with a CDS Pro version soon that allegedly will be the end-all, be-all of designing, what we, the users, have been asking for since the beginning. But they have said that the Pro will be a new program and therefore will require a new purchase - not an upgrade from the current one on my laptop. If that is true, then that will be the last purchase I make with them because I will go get SCAL instead. I am jealous of the stuff that people make with it. I can't even attempt it in CDS.
If you have any specific questions about CDS, let me know.