I haven't driven the new generation Volt so I can't offer a genuine comparison honestly, but here's my observations from what I know and have read.
- People like the interior of the second gen more - less "gizmo", more "traditional", but I kinda like gizmo myself LOL.
- They have the larger battery of course, but that isn't the be-all-end-all for those of whom the range of a Gen1 fits their needs. The latter years of the first generation also had larger batteries - I posted the specs earlier in this thread but they can be found easily via Google.
- The body styling of the second gen is liked more by some...but again, that's subjective - I actually like the first gen body style a LOT more myself - it's unique and turns heads whereas the second generation is far less distinct and kind of looks like every other compact-ish sedan out there.
- The second gen Volt doesn't need premium gas, and gets better MPG when in ICE mode as well. Again, depends on how much you plan to use the ICE - spending $15K more to save $5 per fill up and go a few extra KM on that tank, well..the math isn't hard.
If I were to do things all over again (and we may very well do exactly that, I can see another Volt in our future until Bolt's come down in price in the used market in 5 or so years) I would do the exact same thing over again - find a 2012-2013 in the sub $15K category with at least 30,000-50,000KM left on the Voltec warranty) and buy that.
For us, the math has already proven itself with our savings having exceeded $1000 between gas and oil change savings in a roughly 3 month ownership period.
I've actually been casually looking a Volts in the USA - there are 2011's and 2012's in the 100,000 mile range selling for the $8K USD range. That's under $10K CDN with the exchange rate right now, basically $11300.00 after taxes at the border, and the import process isn't terribly complicated...I've done it before. Yes, with 100,000 miles the Voltec warranty is expired so I would be doing careful due diligence on overall vehicle and battery health before handing over cash, but for what could amount to a $5000+ savings....the idea remains intriguing.