Replace Canon 100-400 V1 by tamron 150-600G2, good choice?

bowserb wrote:

If there is ever a chance that you might go to Canon mirrorless, and you might since even Canon is now admitting that mirrorless is their future, you might stick with your Canon 100-400 v1. Tamron is notorious for fast backward engineering and then needing firmware updates. Examples.

I just bought an M50, while my wife sticks with her 5DSR, 5D2, and 7D. I've gone through all our lenses and found every single Canon EF lens works with the M50 and Canon EF-M adapter. My Tamron 150-600 sort of works, but its slow AF got even slower. My Tamron 16-300 (a crop lens) does not work--AND Tamron has no firmware update. Customer service says, "It will not work on a mirrorless." Period. End of story. No firmware update for this.

We also have the 100-400 v1, and it has worked since 2004 on everything. On the 5DSR the AF even works with the 1.4 extender. Frankly, I'm not impressed with the 150-600, even with a Canon DSLR. Like someone else mentioned, that sucker is heavy. OTOH, I never cease to be amazed at the quality of pictures from the 100-400. It's heavy too, but lighter than the Tamron. The push pull zoom is actually handy in many instances where you can keep the zoom lock loose and zoom quickly wihtout twisting your hand (soccer games, etc.) It truly is a lens we won't leave home without.

Is this still the case where the M50 and the 150-600G2 are a bad AF combo that Tamron officiall says are incompatible? I wanted the G2 primarily for a birding lens and being half the cost of a 100-400L II + 1.4x TC