I agree with the review it was very good (too good in fact haha) Some of my comments are :
I really like the compactness of this lens. While it does not cover the range of my Tamron 18-250 , the 50mm on the wide end comes in handy. I also find it more stable at 300mm than the tammy at 250. The focus noise can be unsettling. I find if I am at infinity already the next shot will focus relatively quick , however the first infinity focus is quite noisy , something that will scare the birds

. I also found it does surprisingly well in low light. Another thing I really like is no zoom creep. This is very handy point the lens up towards the trees. Now this may loosen up over time , but for now it is a non issue. Have not tried too many ‘macro’ close up shots yet. That is my next task
Here are couple of shots from last night. I have a few days left for a full refund return , don't think that is going to happen
Both wide open taken in early evening 300mm f5.8, 1/180, ISO 100
Click on Images for full size
100% Crop
100% Crop
Not bad for a consumer lens at all IMHO