Neil,
For me, my 0.177" HW99S is a true Gem of a rifle, and is one of my favourite rifles.
Definitely a 'rough diamond' out of the box, but with some simple tweaking it has turned into a true pocket-rocket, and a rifle to be reckoned with
My 0.177" HW95 Super Match ( HW95 with HW98 stock & barrel, with open sights as standard ) shoots very nicely indeed, but I much prefer my 99S
The HW95 SM had to have its butt filled with much lead to make the rifle balance correctly - without the lead it was (for me) dreadfully nose heavy.
Have fun & a good Sunday
Best regards
Russ