Alright. Here is a set of shots taken with the 7D and 100-400 L (original). I grabbed a few, with birds of varying sizes in frame, to bring some diversity of pixels-on-target to demonstrate that isn't necessarily the issue with the 150-600. These are all original shots, original crop, no scaling, no processing, no sharpening or NR of any kind. Strait out of camera RAW exported to 75% quality JPEG from Lightroom. (Blame CR forums for links to images instead of just images...I don't know what it was doing, but it wouldn't let me post with them embedded as images.)
Every image here appears to be sharper than the 150-600mm shots. To be fair, one of your shots seems to have some motion blur. For the other, I cannot say, not really sure if there is any motion blur or not, but it still seems a little soft. Not as sharp as either my 100-400 shots or my 1200mm f/10 chickadee. Now, don't get me wrong. I'm a fan of the idea of an affordable lens that reaches 600mm. For the novice or budget birder, I think having such a lens is a HUGE benefit. That said, if the sharpness from your example shots is around the best the lens can do at 600mm, then I'm rather disappointed. I'm happy to accept if the issue is technique, or too slow a shutter speed, or lack of IS use (or IS kicking in and screwing up the shot), etc. If you can demonstrate as much, then more power too you, prove me wrong! But, as it stands, I don't think the sharpness of those shots is what I would call "ideal"...I think my 100-400 does better, and my 600 with a 2x TC at 1200mm f/10 (!!) does better.