iOS 5.1 did not fix all the problems related to smart playlist in the iPad 2 with iTunes Match subscription.
- Smart Playlists based on dates are not syncing across all devices and Macs/PCs. For example, Recently Played.
- Smart Playlists based on play counts are not syncing across all devices and Macs/PCs.
- Sorting of songs in iPad2 is out of whack. iPad2 music app seems to ignore the sort order in smart playlists. this is very annoying since I have a lot of classical music in my library in which track arrangement is very important. I'm not having this problem with my iPod Touch though, just in the iPad2.
iOS 5.1 did fix one of my problems: the Smart Playlists in the iPad2 that are based on the "Comments" field. My smart playlists are now correctly populated with songs.
These are my observations, so far.