Hello jopa66 and welcome to Seven Forums.
I've been using the native Windows 7 backup/imaging tool and haven't experienced any issues. But I also use the free Macrium Reflect "just in case". If you'd like to try some other free backup/imaging tools to see how they compare, here are some more products: Aomei
(also does incrementals and differentials) EaseUS Todo Paragon
From your post, you say you're interested in wanting to "...backup registry and selected other files each night." So maybe you really don't need a full-blown backup/imaging tool. Perhaps you'd be better served using something like ERUNT for the registry and Microsoft's SyncToy or FreeFileSync for your other selected files. ERUNT SyncToy
and How to use FreeFileSync
and How to use