Is it good, yes. Not the best but good and safe to use. No cooler manufacturer would want to try to sell their cooler with shoddy TIM. That would make for loss of sales in a hurry.
As to conductivity, it is hard to say because it depends who they had contracted the manufacture of it out to at the time that particular cooler was made. If it is made with metal particles like Arctic Silver, it would be.
Just pick up a tube of MX-4 when you can. In the mean time use the factory stuff.