In reply to patrick1258:
I think when it comes to common usage and understanding for all in an easier way,
like in SV you can write your UVC/TB in your logic/flow, when it is given to others/integrator it may take time to understand and implement in their environment, hence when you use UVM it will be easier since it is predefined flow,
It provides may methods and mechanisms to ease the coding and usage, whereas SV is abstract,
Factory is useful when you want to override and has some methods which can be used to control the log displays,
TLM communication is little different than the IPC’s we use in SV tb.