I looked at two Gen-1 Insights with the CVT transmissions recently, one at a dealership and one being sold by an individual. Both had issues with shuddering on take-off, and one shuddered so bad there was no way you could drive it in traffic, but the guy said he'd been driving like that since he bought it (doubt it).
After researching the shuddering issue, it seems to be that the start clutch eventually goes in them, so much so that there was a recall for this back in the day. There are fixes like changing the CVT fluid, or burnishing the start clutch plates, but I passed on both cars since there was no guarantee that I could afford a fix, and a lot of people changed the CVT fluid only to have the problem reappear a couple of months later.
You'll still get fairly good mpg in the CVT version if you can find one that doesn't shudder, but I'd hold out for the manual if you can find one.
This is the one I'm trying to talk a guy down on right now:
2004 Honda Insight Turbo Charged Solar Powered