From our experience and using one myself. They actually work very well and for the price. My favorite is the Mighty or Crafty but they are so expensive. For getting into the portable market inexpensively this can be a great option. I would love to hear from others that have used one as well.
The comsic is also a portable on it has a water bubbler on it but mine dropped and broke (the water bubbler). It came with a bluetooth app to download as well for temps. Personally I don't use the portable to much and just bought a plenty.
Anything from Storz and Bickel is a good call. I like to use the Volcano as my main at home vaporizer. I will have to check out the cosmic. I have not seen that one yet. Did you like it before the bubbler broke?