Notice My opinion only.
I am air savant lvl 20. Just recently I went to water do to water savant saying omg to water.
I changed all my spells mostly to water and cold with back up to lightning. I am not uber decked out just hit lvl 20 recently. I also changed some of my gear from lightning to cold.
In my opnion, I wasn't wowed by the cold spells dps. First off, 1st SLA, inless you have very high dc is big waste on time and damage. If it does hit, it hit very well on crits but I wouldn't rely on this SLA. whereas, 1st for air is touch spell that hit's decently well and doesn't miss. The Second snowbow was ok very short time aoe spell. The dmg wasn't that much greater if at all to Air savant. Third to me was ehhh seemed equivelent to lightning bolt.
Now in epic dungeon runs where I did my test, you really can't be using anything other than SLA or you gonna run out of power quickly. Those other spells COC, OFS, PR, etc. Are just not really mana efficient for epic dungeons.
The red boss I did was minatour and I ended up using atleast a quater of my power to take him down. I was hoping for the big hits of PR but it just wasnt mana efficient enough to take him down. In the end, I realized I was wasting way to much power to kill this one epic red mob so I ended up kitting for 10 minutes to kill him with SLA. Yes I used niac biting cold and reduced his resistance to cold damage every chance it came up.
When I was in air spec it was about same result, I ended up having to kite him to use SLA to kill as well cause the other lightning spells weren't mana efficient either. My opinion inless your doing non epic dungeons yea you might be wowed. Epics though inless your really decked out you might not be so wowed.
Also the nerfed to Ice prison makes cold less appealing to me.
Things I missed from air, Mobs knocking me down!!! Ack down I went and death follows soon.
Second My trap avoider the wind dance! Everytime I knew where trap was, I hit that wind dance and blast through the trap = Sweet. Not to mention, I can jump over deep holes without a problem.
I give ice little more chance But ehh I am not that impressed so far.