** Apple: Let us selectively upgrade songs **
There are plenty of benefits to the iTunes Plus format, and I've been buying them when I can since they were first introduced. As a reminder, songs in iTunes+ form cost the same additional 30 cents when they first became available. After a few months the cost dropped from the 1.29 to the 99 cents consistent with non-plus files. I've occasionally upgraded my library and the process works OK, though there are problems with large downloads, and I seem to remember having issues where I had changed the meta data (album artist, composer, etc) and that data was lost when the Plus versions replaced the originals.
My problem, like many of you, is that doing all my tunes at one time will be costly, and if there are any issues with the replacements I will have headaches for days. Today I am offered the opportunity to drop $236.10 upgrading 794 songs, but unfortunately that will still leave over 800 more Protected AAC files to be upgraded as they dribble into the store, for a probably total cost of over 500 bucks.
Like several other posters here, I have tunes that I purchased for my kids, for one time events, by mistake, that I don't like, that I subsequently bought on CD, etc, and I just can't see upgrading all of them. And let's not forget the files are larger, so if you're close to a full iPod like I am it will cause issues with it too.
I guess if it is all or nothing, I'm going to have to choose nothing. Apple, if you're listening, please rethink this policy and come to the rescue of your best customers, because the more we bought in the past the more we have to spend now to upgrade the files.