This week I tried both Google Music Manager and Amazon Music Importer again. Google was unusable and Amazon needed some work to get it functioning. Even when working properly, Amazon Music Importer will not work with the Chrome web browser.
Google Music Manager would not work properly. I would try to bring up the application from the task bar and it would close itself before I could click on anything! I uninstalled and re-installed it with no improvement so I just removed it from my PC.
I had better luck with Amazon Music Importer. I uninstalled it, updated Adobe Air, re-installed Music Importer and then it worked with Microsoft Internet Explorer 9.
Amazon claims some problem with Flash and the Chrome web browser so you cannot use it to upload music. However you can play music with Chrome, so I guess from time to time I will just use IE 9 to upload my music.
Finally Amazon's music matching service seemed to work well, it will even match ogg vorbis and flac music files. It matches them with high bit-rate mp3s though. I prefer Amazon's look and it seems to match graphics better to albums than Google does. Neither is great but Amazon is the better of the two fairly bad cloud services.