Does the 23" one not overlap on the LHS pillar?
The OEM are 22" IIRC?
On most modern vehicles, the wiper blades can not be seen when fully down, they recess into the window valance. On the hippo they sit up high on the window.
I started a wiper thread few years back
http://www.landyzone.co.uk/lz/f9/front-wiper-blades-138940.html
I didn't like the aero blades, especially the big plastic connector, it was an eyesore!!
Having looked at the Pound shop versions they have that classic look, which IMHO suits the Hippo,
Pointer - keep the U shaped plastic attachment clips as spares, cheaper versions can be brittle