I had a very similar dilemma a few months ago...

The 99 is nice and light (maybe not what you need in springer) and a fiend has the .22 and it shoots very well , but I wanted a .177 and the firing cycle tends to be harsher in that calibre so maybe would have been less tolerant of the lack of mass.

The 95 was the other option - a bit heavier, but not quite as heavy as the 98, same mechanicals though and a decent price too.

BUT I did so want the 98's stock and I thought that it was what I wanted in the first place, so if I bought something else then i'd up regretting it and end up still wanting a 98.

So I bought the 98 in .177 and Yes, it's wee bit heavy - BUT it's super-accurate, comfortable and completely un-fussy of its diet of pellets...Am I happy with it? Hell Yes!