Legacy glass with NX

As a potential buyer of a NX300...have the preceding versions had any issues with RF wideangles or any other legacy glass (As the NEX7 did)? Currently use a Nex 5N, and often shoot at higher ISO settings, don't use much if any PP (yet), so I know the new NX will need improvement at higher ISOs with JPGs. But mainly I use legacy lenses and would appreciate feedback about their use. Thanks