Basic service is all I need, it gives me:
1. When the engine quits or things go to shyte over the highlands I don't have to spend the valuable and limited time I have "introducing" myself as they already know even without radar coverage who I am , where I am coming from and going to, and what my current approximate position is based on the average speed of a spam can which should be enough to vector the cavalry to my approximate position then my fancy ELT that's registered with the emergency services will hopefully pinpoint my position from there and allow them to deliver any emergency resources needed such as first aid or Marlboros.
2. As for advising there is/may be other traffic, it's nice to have but unless I am flying under positive control I am never relieved from devoting 100% of my paranoia to my see and avoid duties.