I gifted my wife GM this year and she was 5 for 16 in upgrades, all on SM tickets. Only one of those was a longer flight and it was all battlefield. I'm not planning to do it again but I am holding onto my choices until I need a GUC or plan a trip with her and then I'll decide.

If the route you plan to take makes it down to GM sometimes, it might be a better deal for for you than it was for me.

Of course flying on SM you go to the bottom of the GM list.

One thing I am not sure of is whether it affected her getting pre-check. We are always in the same PNR and I have Global Entry. But she has gotten it 100% of the time. Maybe she got it for being with me and maybe she got it for being GM, not sure.