So, the Marketplace Dashboard update almost made it through testing! The biggest problem turned out to be it's performance on low-memory phones like the Nokia Lumia 610. I was surprised since I knew that it ran fine, but it ended up being more subtle than that.
First of all, you should know that background agents won't run with 256MB phones. For that reason I was already hiding the option for that on those devices (and feeling pretty smug about it!).
|Lumia 610 (256MB RAM)|
Bottom line, it's not just peak memory that you need to worry about. With less memory, things can run slower. If you are using timeouts, you should probably increase those too. Unfortunately, that part's going to be hard to test on the emulator. You can only do your best though! Being aware of this might save you some frustration later.