@ DarkestSamus: Minor correction, Freeze Shock has 140 base power, not 150.
http://www.smogon.com/bw/moves/freeze_shock
Just thought I should mention it :)
The problem with Freeze Shock (and similar-ish moves like Hyper Beam, Giga Impact, Sky Attack etc, etc) is that while you spend a turn 'charging', your opponent won't just be sitting idly by. They will be attacking you, they could be setting up on you, or doing any number of nasty things. Seriously, in pokemon, there are few worse things you can do than simply giving your opponent a free turn to do whatever they want. Worse still, not only are you giving them a free turn, but in the case of Freeze Shock, your also telling them EXACTLY what you're about to do, no prediction required.
Another problem with this move though is that, if you're going to be spending two turns attacking anyway, then why not just click Outrage? Dragon and Ice are kind of similar in offensive coverage; both hit Dragons SE, both are resisted by steel. Ice is SE against a few more things (like flying, grass) but when you have 170 Attack, does that really matter? And besides, Dragon just has better neutral coverage. There is the confusion I admit, but if that's unappealing, then even Dragon Claw is probably better. I mean, two Dragon Claws in a row will out-damage one Freeze Shock (DClaw= 80+80=160, FS=0+140=140, if you get what I mean).
Also, Freeze Shock is only 90% accurate. Imagine spending a turn charging, only to waste another turn missing... :p
Oh, and with BROStime's set on the previous page; if you're going to use a subroost set, I personally prefer Leftovers for the item. IMO the elemental plates suck on anything that's not Arceus; Lefties will give you a bit more staying power + recovery from sub. If you want a power boost, I suppose Life Orb is an option, though that residual damage will rack up.