Even I haven't tried them yet, this isn't like taking a name brand or trying a generic or off-brand that is basically the same thing.
These things aren't regulated, you should probably go with a company that doesn't have any bad reviews or known to have any bunk stuff. In the end, you should just do your homework and dig out all the dirt you can find on any company, because this is the internet, and information is out there if you want to find it.