Stormrazor will be a bad starting item.
Stormrazor + a Shard, however, will be pretty good. Keep in mind that Shard is only 600g now, down from 800.
130 magic damage (right? Pretty sure that math is correct; 501.3 + 501.3) per Energized attack, plus an ultra-annoying 40% slow. Doesn't sound so bad!
So, my advice is to never rush Stormrazor after next patch, unless you're getting at least a Shard immediately after. Then it might be pretty good.