Nice soft image of a Cardinal male Jack- and I don't mean unsharp. I think the colours and light combine to give the impression of softness. The BG is beautiful, although maybe softening those up and down lines TR would be useful. The main issue for me with the image is how imbalanced it is with all the action happening LR. To counteract this to some degree, a tighter crop taking off quite a bit from the top and left would work. If you wanted a wall-hanger I would consider a few sticks and generally cleaning up the greenery a bit. I would also sharpen the bird a bit more, only a bit.
John, what a lovely, soft cardinal image. I also agree that you have way too much negative space in comparison to the bird and that's putting him way too low in the frame. In an typical image such as this, the eye of the bird would be in the UL ROT's area and here it's more centered and down in the lower 1/3 of the image. A good guideline for bird portraits is to let the bird have 50-70% of the frame's space. Of course, there are always exceptions but it works 90% of the time.
We also like it if you can tell us how much of a crop this is and what all you did to the image in post-processing (levels, curves, saturation, etc.) This helps us make further suggestions so keep that in mind for next time.
I think sharpening for web is a very personal thing. I usually go along the Artie route:
Select the bird or any other element you want sharpened
Run USM at 125/0.2/0 - repeat this 3-4 times.
If the eye still looks as though it needs to be a little sharper I select it alone and sharpen more to taste