Internally speaking, the three Weihrauchs that I've had had terrible fit and finish inside. I've had, what six Dianas that ranged from terrible internal fit to very good, like my 2015 350 Mag.
My HW95 had horrendous twang, buzz, kick and shake into well over 1 000 pellets, never getting better. My D48 also had a terrible shot cycle when new, but transformed into a very smooth gun just by shooting it in.
I'm partial to .22 cal springers, and in that caliber Diana barrels beat Weihrauch barrels fair and square. I will never buy a .22 cal HW again, while I will buy more .22 cal Dianas.