I've never rated him personally and rate him even less now that he's getting old and our side is getting stronger. Unless we're crippled with injuries there is no way he should be getting in our starting XI nowadays.
The problem with him has always been he's not consistent enough. Every season, on average, he plays about 40 games, in the league and the cups. For 10 of those games he'll be great and will score important goals. For another 10 he'll mediocre/unnoticeable. And for about 20 he's just utter garbage, a liability in fact.
He's now starting to be slowly phased out as better players come in to fill his position but this should have been the case 3 or 4 years ago I feel. Moyes seemed to absolutely love him and he wouldn't be dropped no matter how badly his form dipped. Martinez seems to like him as well and gives him more opportunities than I think he should be getting but at least he's not a guaranteed starter EVERY week like he used to be.
Osman has his uses as a player, don't get me wrong. He's handy for experience in a game where there might be a lot of youngsters on the pitch. Just I've never thought of him as this unappreciated gem of the Premier League like the media and many supporters make out he is. For me he's just an average Premier League level footballer, can have a great day sometimes but the mediocre and bad outnumber the good.
Hopefully when he and Hibbo and decide to hang them up they get coaching roles of some sort, they deserve that for being loyal all these years. Just when I'm an old man and I talk to my grandkids about players I saw when I was young, Osman won't be one I'll be eager to reminisce about.