Not overpowered, that's for sure. Nothing working on physical damage can possibly be overpowered nowadays, lest you be using a Windy.
Although Strafe will be rather slow, it's still useful as it's not as badly mana intensive as Multishot will be. Almost as good to reload mana as guided, and it may be faster whitling away bosses. Still, I've noted that the extra effects seem not to trigger on Strafe (level 15 nova, etc).
But it's with the cold tree that the set shines, truly. And perhaps it's the one build where your optimal amulet happens to be Crescent Moon. 15% mana leech will do wonders here. Anything with mana leech is good, as you only get 5% mana leech with the whole set, which won't do unless you are really good at switching attacks. My own Mavinette uses 2 low grade dual leech rings and a 8% mana leech rare amy, and she can more or less sustain Freezing arrow as long as she hits and the target can be leeched.
My own Mavina set is rigged for MFing (2 Ptopazes), and default attack tends to be Multi until I find a ripe target to freeze. I have Nefed my bow, but I may choose to change that for more damage or a cold facet unique jewel--I found a low grade one. So many cold immunes in Hell. I found that RoF is a good generic place to hunt for her, as there are not so many Cold immunes down there. I do Hephaistos Run. And I use a lot of Decoy scouting. One is never too careful when he soloes.
9 is the first attack in the strafe cycle, which is the same as a regular attack. The 2 is the actual strafing.. which is something like 9/2/2/2/2 I believe.. maybe more. So a full frame cycle, in this example, would be 17 frames a second, or 17/25 seconds. Someone correct me if I'm wrong.