I walked it in weekend sections in the nineties. As it's quite a while ago now, a lot of the detail has faded but I remember I enjoyed the solitude. As you say, it's not noted for the hills along the way, there are one or two at either end but it's essentially a fairly easy country walk with pleasant, rather than spectacular scenery. Some things I remember are overgrown paths, missing waymarks causing difficulty with locating paths across fields and flooded sections when I did it. There are a number of attractive villages, particularly Bourton on the Water at the start and it also passes Blenheim Palace. Not a particularly memorable walk but enjoyable in it's way. Have a good walk!