I'm sure it will get at least +30 speed. While base 100 isn't great, it's still respectable enough. I also hope it gets more, of course.
I'm not worried about its damage output, Tough Claws makes it hit just as hard as LO Metagross, and that's ignoring its increased attack. I'm on mobile so I'm not gonna do a calc, but if Megagross got, say, +20 in attack (worst case scenario), it would be hitting about 15% harder than LO Meta, I believe.