"corners should be round" Theo Evo .22/.177 - Meopta 6x42, DS huntsman classic .20 vortex razor LH 3-15x42 under supervised boingrati tuning by Tony L & Tinbum, HW77 forest green - Nikon prostaff 2-7x32 plex.
I don't remember ever trying one. Which isn't always a good thing.
Once I thought I'd never owned a .20 cal, until by chance I found the sales receipt for a .20 Fenman that I must have bought.
Anyway, I trust Tinbum, and I think he said the 99S should be the best springer ever - but it just isn't.