Though I haven't tested it tbh, it's probably not worth it.
The 50% cooldown reduction sounds huge on paper, but since cooldown only accounts for about a third of the total delay between shots you'll most likely only gain a meager ~15% DPS increase. Now that isn't awful by any means for an essentially free buff - but the downside of +20% received acc makes this quite a gamble, considering snipers aren't too durable to begin with. Simply too risky to lose your sniper to a couple of lucky max range shots in exchange for a mild DPS boost...
The +20% higher accuracy won't be noticeable in most cases either, as the sniper can't miss regular inf to begin with. Unless, of course, you're trying to hit retreating squads. Here the higher accuracy could very well make a difference, though I'm not sure by how much. Maybe someone else can and will elaborate on that.
Interesting. So maybe it's worth it for taking down retreating squads.