I have always used icon packs, but now i decided to just use stock and it annoys me so much that some icons are HD and some are not, why can't the developers make them HD?
All depends on how much the Dev cares about the app and their users. It's a shame that all devs didn't include high res icons from the start of HD displays.
I believe someone answered this in another thread. Basically with all the various screen resolutions, installed memory, various versions of Android, etc out there it is not really feasible for developers if they want their apps on as many devices as possible.