Ever seen the movie "True Grit"? There's Duke, in the courtroom, getting the business from a defense lawyer and a judge when, in response to the defense council's questions about the status of his side arm upon approaching the bad guys, he states that 'A gun that ain't loaded and cocked ain't good for nothin'.
I've been shooting springers for over three decades. In the field, I carry them cocked for hours on end, sometimes, but I'm generally shooting at game within a half-hour of leaving my rig, so I reckon I don't leave it cocked all day long. Carrying my rifles in battery probably DOES shorten the life of my mainsprings, but I replace the mainsprings and seals on my rifles bi-annually as a matter of course, anyhow, so neither I or anything I shoot with them seem to notice any serious degredadation in performance.
That said, most of my spring-piston experience (aside from a pair of Webley Omegas back in the day and a more recent flirtation with a Theoben Crusader) has been with R-Series Beemans.
YMMV, and all of that.......
-JP