Hi all,
First of all, I don't own any Hybrid, but my friends does – both insight and Prius. I have to admit that I'm a fan of Prius simply because it's an icon or representation of 'Hybrid'.

when you mentioned a hybrid car, chances are the 1st car came to people's mind is Toyota Prius, even Hollywood movies use Priuses.
Anyway, I'm not here to say Prius is better than insight then just run away. In fact, if I were to choose between these 2 cars, I would go for an insight. Why? it's because insight is a very simple car, the idea, the design, bla bla bla... I think that's why the design and engineering is not same as Prius.
After a few rounds behind both wheels (insight & Prius) on long distance drives, I found that prius is a great car to be in, but you will have to try very hard and get-use-to to really save fuel. Unlike Prius, Insight is so simple that you don't have much choice apart from just drive with ECON on/off, S here, D there and it works. I does save more fuel compare to Honda City driving under the same condition

With Prius, you really have to be gentle on the gas to yield better mileage or be hard to just go fast. Yes, similar goes to insight. But I must say that, for Prius, it became annoying when sometimes you just want to drive like normal but often you will feel that there's not enough power to go up a slope (because the car think that you are in 'eco' mode and try to conserve the energy for you) and when you want to go fast, it will take a while before you can feel the throttle (the delay is quite bad).
I'm not very good at describing these 2 cars, but if you draw a line with fuel saving in 1 end and going fast or response in the other, Prius has got longer line at both ends, and it's the longer line that annoyed me. This is the factor that makes me think insight is a simple car and I love the simplicity of it

It's a bit like a DSLR and a point & Shot camera case, sometime i don't need a DSLR to do the job
Sorry for the looong reply, GTG, bosses are around

So comparing those facts with 41k different price tag, everybody knows the answer of which hybrid better.
From my interpretation on the comments in autoworld, majority of the commentor are not Insight owners and their comments are quite blunt with no actual facts.
There are comments that
Insight is not for those who want to save money!? If want to save money, drive DIESEL car. Haha..
Ultimately, check with Insight owner, and ask them the FC and how much it save their money.
My ride FC is approximately 18-20km/l, which I dun think City, Vios, Civic, Altis can deliver. Correct me if Im wrong.
I saw toyota/ prius fan also in that insight forum try to down insight and said prius better bla bla.
Maybe they're toyota salesmen trying to get some sales for that expensive prius.
We all know Prius not worth a penny here....