I've been studying this same topic for a new lecture coming up and a quick shout out to Bob at CAP for being unbiased and sharing his knowledge on this topic with me, thank you!!!. Trios is by far the best from my studies. However, it has it's flaws too... one is the price, nearly 40K, plus a yearly license fee of 3,700 and the shade matching ain't exactly spot on, but the pictures are there. What really turns me off (and maybe it won't for the Dentists) is all the extra fees. Similar to 3Shape, they all have licensing fees, and my philosophy on that is if I go buy car off the dealers lot, It's mine, it should work. Sure, you might need some maintenance but it shouldn't automatically shut off if I don't pay the yearly license fee, especially if I don't want to update it. Heck, most days I'm just happy it gets me to work and back. As for different systems, you have Tru-Def (3M/Jensen) 12K, plus 250 a month to open .stl, plus marking margin fee (unless you get certified to do it) Which pisses me off, I can do a full mouth resto but can't mark a margin??? Come on 3M!!! E4D is similar to the monthly cost to open a .stl. I believe the last time I checked it was around 250 dollars/month. As others stated, E4D and Craperec was meant to be a chairside mill and although you can get Cerec sent to you and a model milled, the accuracy is junk. It might work for some labs, but microscope labs won't do it, including me. Itero has worked great, the accuracy was very reasonable, but at the time we were doing them, they milled the models and it that ruined the surface texture and all the additional fees associated with the models, software, and it's a bulky machine. Still looking into CareStream, waiting to hear the cost and workflow of this system. I will say more Dentists are asking me about this and there seems to be some hoopla about intraoral scanners, that way out of state clients don't have to ship, the legalities of the assistants, and eventually going modelless. Please feel free to comment or add to this, as any information is helpful.