Funnily enough I don't recall doing a LGU review as I've never owned one. Do you have a link to it? However I have shot one extensively and found it very smooth. My main experience is with the LGV.
To answer your question my criticism of Walther stocks could be applied to most of the OEM offerings from all the German makers like HW, Diana and Walther. However the difference is that all of the well known after market stock makers make for the HW range and that is very important. Even after the demise of GINB there are still plenty around from which to choose. My personal favourite is the Custom Stock CS800 but the main point for me is that the stocks should be available in WALNUT. I cannot stand beech especially beech stained to make it look like walnut.
For the Walther LGV/LGU just making the Competition Ultra stock in walnut and giving it an adjustable butt pad would be a great start. Other than that the standard sporter -like my 'Challenger' synthetic with an adjustable butt pad made in walnut would do for most shooters.