Gas struts have certain advantages, consistency is one of them, another is the ability to have a rifle cocked for a long time without a reduction of power.
Struts have been around in air rifles for about 40 years, they tend to make cocking harder, but do deliver a non-twangy delivery of power! I am not sure how struts fluctuate under temperature differences, I know springs do to a degree, thus struts should do the same?
Personally I think springs win overall, even on the twangy sound, grease is your friend
Candocad.