Somebody over on the destiny subreddit
did the math:
"In September the icebreaker is having its recharge time increased from 5 seconds to 8 Yea, so guess what that means kiddies! 1 bullet every 8 seconds is equal to 37 bullets in 5 MINUTES. Synth cool down. That means you get 43 bullets (37 plus the original 6) for your icebreaker in 5 minutes, you can't get any more than that. On a sniper with a reserve of 18? 36 in 5 minutes. And you can DPS burst that on bosses, instead of a bullet each 8 seconds. You wanna give your exotic slot for less DPS and 7 more bullets? Fine by me but I'm sticking with pretty much any legendary sniper.
OH YEA And icebreaker can't pick up more special, making legendaries even BETTER Fuck me BUNGIE this is dumb...
TL

R icebreaker now has less DPS than every high impact legendary sniper, and you're giving your exotic slot for 7 more bullets in a 5 minute window."