Hello,
I have a little problem with the image quality of the first post (the one in the header). In my opinion, I think the picture quality is a bit worse than the original. What can I do?
and one more question =): Can I also show popular posts with WP Show Post?
Any sort of image resizing can result in quality loss. To keep the original quality, you’d need to display the original image without any resizing done to it. Alternatively, you could manually resize it in something like Photoshop.
WPSP isn’t set up to query posts based on things like popularity at the moment.