Hi Paolo. Rather than pasting a link to an image in the message body, click the Insert Image button and paste your link there. Your sharpness looks pretty good. I would have liked to have seen the bird flying towards you instead of away from you though. I also prefer the wings fully up or fully down. Thanks for sharing!
Congrats on a sharp image, agree with Doug, but would like to add:
The histogram for this image shows nothing in the right fourth and this is basically
a white bird, one which could be much brighter, probably EV should be + by 1/3 to 2/3.
Also, you have presented in Adobe RGB colorspace, best to "CONVERT" to sRGB for
web presentation as many browsers will not interpret Adobe RGB properly.
This is only a slight levels adjustment and still has plenty of highlight headroom.
I like it! Plenty of room to increase pop in post-processing. The main trick is to mask out the subject so you can edit bird and background separately.
With clean edges like this, it isn't very hard to make a decent mask. Nice work.