I vote to edge of upper cabinet.

Follow upper cabinets, 1st pic.

Another vote for lining it up with the upper cabinet.

https://www.flooranddecor.com/glass-tile/andes-silver-linear-glass-tile-100968882.html

I am installing tommorow and thank you all for help with re-enforcing my belief end the tile with edge of upper cabinetry. The tile guy was suggesting going past cabinet and it looked so wrong. It will be 1 1/2 short but hopefully the tile will just look so pretty. I also am using Mapei Ultracolor plus "Frost " 77 It is white with slight grey color .

I also agree to end the backsplash with your upper cabinet.

Do the cabinets go to the ceiling? If so, tile to the wall, go down to the floor and up to the ceiling. You will have a more polished, visually seamless look.

I would not go past the upper cabinets and tile the whole wall to the ceiling. Doing so will take you down a rabbit hole of where to stop. There's a door to the right which will require you to decide if it ends at the doorway, over the doorway, into the adjoining room......just no.

I'm surprised that your tile pro suggested ending it at the counter edge. My tile guy was adamant that it end with the upper cabinets. It looks weird to have that right angle of tile sticking out.

End at the cabinet

I don’t mean to be rude but most installers are not designers. The Houzz group gave you the right answer.

Yes, installers are not designers, but a good tradesperson knows what works best from a technical standpoint.