Having spent some time in South America, mate sure is nice and a good change of pace. In the countrysides, it's not uncommon to see people with large thermoses slung under the elbow (for hot water) and a mate gourd in the same hand, happily sipping the days away. I'd recommend it for anyone looking to add some variety in your daily routine. Be advised that it is an acquired taste and may take a week to get used to, just like coffee was in the beginning.
[0] https://en.wikipedia.org/wiki/Yerba_mate
[1] https://www.amazon.com/Guayaki-Traditional-Organic-Yerba-Loo...
[2] https://www.amazon.com/Mategreen-M0035-Argentina-Yerba-Gourd...
(though there are cheaper gourds that can just sit without tipping, I prefer the traditional hand-held ones)
Drinks such as coffee have a ton of caffeine in comparison. A cup of coffee has around ~200mg of caffeine, while yerba mate drinks have around ~70mg: http://guayaki.com/caffeine_meter.html
So drinking yerba mate is a lot like drinking tea as far as the caffeine experience goes.
That said, yeah, mate is pretty mild in terms of caffeine content.
http://www.latimes.com/health/la-he-skeptic14-2008jul14-stor...
This sounds very dubious. Caffeine has only one stereoisomer. And if you mean a structural isomer, then it's not actually caffeine any more.
I find stories like this to be important reminders that it is likely happening around me, and I need to be alert for it.
I’ve personally never come across anyone who (admits) to using anything stronger than Redbull. In fact, we have some employees who don’t even drink coffee, opting for “natural” stimulants which come with less of a crash. Yerba Mate seems particularly popular these days.
However, I may be in my own bubble; I’m very interested in seeing what you find!