Has anyone tried this combo. Running the numbers on Quickload it looks promising. Anyone have any real world experence?

Not sure what bullet weight you are looking at but have had good success with 550 and a 140 gr. Here are the component specifics: Lapua 308 brass necked down, Rem 9 1/2 LR primers, Nosler 140 gr. BT mollied. Was able to safely achieve 3110 fps from a 26" barrel. Accuracy was outstanding considering the high velocity with 3-shot groups averaging 0.668". If you used non-mollied bullets or a shorter barrel, I'm not sure if you could get as much velocity as I did. My top end load that gave me the 3110 fps filled the case to the bottom of the neck if memory serves me right. I haven't shot this load in quite some time. I currently use VARGET and AA-4064 for velocities in the mid 2900's and sub 1/2" accuracy. But for speed, 550 is definitely the winner. Hope this answers your question.

How about with N560? I have difficulty achieving decent velocities in my 7mm-08 although it doesn't bother me much, I am currently shooting the 162gn bullet with a mild load of VVN140 at something less than 2500fps which might not be impressive on paper, but it is accurate and kills just fine. I took a chamois at 465 yards with it in November, dropped on the spot, as well as a few deer and pigs.

However, it would be nice to get to 3000fps with a 140gn or maybe 2600 with the 162grainer.

I never tried N560, and don't have any N550 in my workshop.