1880-S Morgan- Your Opinion On Grade?

Morgans are tough to grade due to the wide variances in strike quality, even within issues from the same year and mint. Generally, though, you would expect an 1880-S to have a strong strike, because the master dies were still sharp. Based on that, I believe this one to be about AU55.

The early S-mint Morgans are known for sharp strikes and outstanding luster. That's probably why so many have been slabbed with MS-65 and better grades from the top TPGs.
Your coin looks very close to mint state, but it has weak detail in the hair above Liberty's forehead. This area is usually pretty sharp on MS Morgans, so I suspect this is a sign of wear. That would make this dollar an AU and it would not be worth spending the money to have it graded. I personally would not send in an 1880-S for grading unless I thought it had a shot at MS-65 or better. I would leave this one in a nice 2X2 holder or album and save the grading fee for another coin.
As far as which grading service to choose, I would pick PCGS or NGC.