Big difference
Midwestern, you have no idea how different the two bikes feel. Firstly the Specialized is a bastardised Langster ‘fixie’, which took me forever to get used to. That's what I ride to work everyday (90km round trip). I've just finished building up the Argon 18 and it's stupid light. I haven't put it on a scale yet, but I'm sure it won't compete with the really light toys you see on this site.
The feel of the bikes is the big difference though. They have different top tube lengths and different seat tube angles, which make them like chalk and cheese even though the saddle to bar length is identical.