Seems most of this has been covered pretty well in the last several posts, but I think one thing to keep in mind with this ingredient is that boosting testosterone is not the main selling point (I could be wrong, everyone does use things for their own purposes after all). I've always viewed it as more of a body composition "booster" via strong cAMP boosting. You have things like Forskolin that directly boost cAMP (using the example as a reference point) and Forskolin also has downstream effects on hormones (like Testosterone) as well, but the main selling point is its use in boosting cAMP to free up free fatty acids to be burned (fat loss, fat mitigation, and/or body recomp). Something like SR (Symplocos Racemosa) is a PDE inhibitor and PDE breaks down cAMP so therefore SR also increases cAMP (in a different way than something like Forskolin, which is why they work synergistically together to great effect). PDE inhibition can also help provide some pumps, muscle fullness, and other downstream hormonal benefits (like on Testosterone).
I don't want to fully short change the Testosterone benefits from SR, so don't take this as totally down playing it. Just more of how my point of view looks with these things. Something like SR would be my choice when focusing on higher benefits to things that shift body composition, with Testosterone boosting as a cool bonus that helps, whereas I would look at something a bit different if I wanted something that gave more of the stereotypical "feels" that people get with boosted Testosterone (like mood, vitality, etc.). This doesn't touch on everything it could potentially benefit either.
I'd also not be sure if major shifts in hormones is something I'd even be looking for with taking this and getting bloodwork. Not saying it won't help, not saying you shouldn't necessarily care, but more that again you probably won't be measuring and testing to see these boosts in PDE inhibition, changes in cAMP, etc.
It is a great ingredient, been a fan for awhile now.