The KM 17-35mm f2.8-4 is a nice UWA lens on FF. It is soft wide open but you don't often use a UWA wide open. On APS-C it's not as good as it's no longer UWA and has a limited zoom range.
After receiving all your comments
tamron 17-55 2.8
sony zc 16-80 3.5
tokina 11-16
i love to get them all but funds will not allow