To make one thing clear. In both apps, I used upload on WIFI only. In Google+ this never worked correctly, with or without Auto Uploader. Sometimes the G+ app uploads photos with reduced resolution , and most of the time they get ignored. With the other app, it always works, and uploads your photos in the original resolution.
After I made some photos before I returned to my WIFI later, I sometimes experienced a big slowdown of my phone (Nexus S / ICS 4.0.3 and 2.3.6) and often, the notification bar disappeared or has the Auto Uploader message sitting in the bar forever. Even killing the app does not work. You'll have to reboot before it's gone.
And recently I found out when this happens. If Google+ starts instant upload and Auto Uploader starts to upload, too, something interferes badly. Not only the internet connection is getting slow of course, but the whole phone gets unresponsive and extremely slow.
I think the problem is the bogus Google+ app. I don't know why instant upload never worked here. Looks like all Googlers uploading their photos instantly over 3G, too. Well, I'll guess they don't have to care about data caps :) Looks like they never really tried that feature.
However, I turned off instant upload on the G+ app and use the other. Like I said, it doesn't reduces the image resolution and is therefore a much better solution anyway.
And yes, it's available on the market.
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