I’ve had both Belcampo and the Silverton blend from Huntington. I’ve also had A Cut Above’s burger blend and ground my own.
Of them all, I think the flavor of the Belcampo blend is just a bit superior. It has a bit of a deeper beef flavor. However, keep in mind that I actually like the flavor of grass-fed beef while many prefer the corn-fed. I also prefer the the slightly coarser texture of the Belcampo burger blend.
That said, the difference isn’t HUGE so don’t go way out of the way to get one over the other.
Last, unless you’re dealing with some blend that purposefully pushes the fat to absurd levels, you will be perfectly happy with the fat levels in any of the blends mentioned.