Martin:
I do like it. I wish S&B products were more available here in the USA. We do have a good supply of some calibers, but not the calibers and loads more popular in Europe or elsewhere. A company here in the USA, Ballistic products, makes specialty shotgun wads, slugs, tools and other reloading materials.
They have a similar design, but with a longer wad column. They have these for bore size ball and then an undersize ball that will fit inside a standard shotcup.
The wad you present from S&B would solve the "choke" bore issue, or at least that appears to.