I took the plunge and uploaded my stuff.
Took a couple of days of constant uploading before it finished, but now I've essentially got a 3rd backup of my music. Granted, it's not the same as my other backups which have lossless; but it's better than being left with nothing if worst came to worst.
Anyway...
I'm still not a big on the idea of the cloud as a replacement for on-board storage. My phone/mp3 player is always going to have to have at least 32gb of internal storage (preferably more). But I can definitely see the cloud as something that I could use to supplement the internal storage. (Or to use the cloud on a secondary device like a tablet, where music wouldn't be a priority to me.)
That said...
I am a little disappointed in Google's own "Play Music" app that I must use to stream my tunes from the cloud.
It's a little disorganized, and---on my phone---maybe a little bit slow. It doesn't sound quite as good as PowerAmp, even after installing some 3rd party equalizers. But my biggest gripe is that (at least on my phone) for some reason the "Play Music" app will stop playing music after a couple of minutes once the screen backlight turns off. I've read a couple of comments where some other folks have had that issue, but it isn't everybody; so that is obviously phone dependent. So that sucks. Right now the only way I can keep the app from shutting down after the backlight turns off is by plugging the powercord into the phone and charging it. Weird, I know... but my Pandora app is the exact same way. Oh, well... at least I can hope that my next phone, or maybe a future cheap tablet might work with this app properly.