I have a copy of Tamron’s 150 - 600mm G2 lens. It has really good image quality and is easy to use. I have heard the one you are asking about is similar. Will you be able to test it?
The only drawback for me with my lens is after carrying it around for a while, it gets heavy and so on the tripod it goes. Also, it was not a FX mount lens, so I use a Fringer smart adapter, but that has never been a problem.