I personally have always preferred the CACI to the other suppliers I have tried, which is why I chose CACI for my own salon, but it's always best to try out a few.
CACI is really the pioneer in the microcurrent market for beauty & is the name that is synonymous with the treatment in the majority of people's minds. I get a huge number of hits on my website everyday from people searching for "CACI face-lift" not for "microcurrent", which tells a story in itself!
Also, when we took on CACI the rep was very helpful in arranging & coming along to help out with a demo day for clients. I've not ever had a problem with the machine or company in over 7 years. I currently use the CACI Ultra, which has been worth it's weight in gold, and earlier this year I bought in the Hydratone add-on for the treatment, which successfully upscaled the client spend further.
Alhough expensive you often get what you pay for, and there are a number of purchasing methods from rental, HP etc to buying outright.