@coloco Yesterday I tested and was improving AndStatus to work on my 6 years old Google Nexus One (with Android 4.4.4 firmware). And I made some progress in optimisation of a background work.
However, such an old device has very limited ability to execute tasks concurrently, this is why with default settings AndStatus may show no progress for minutes while e.g. large timeline is being downloaded in a background.
So for old and slow devices I would recommend to turn off some or even all asynchronously working options (see Settings -> Syncing): Turn off Syncing Indicator in a Timeline, disable syncing while using AndStatus...
nonameko@quitter.se