Basically, if you look at it on paper alone, the 2.0 is a more economical and more sensible choice. But the difference between the two in terms of economy is very marginal and the refinement and extra grunt (which is nice to have there when you want/need it) of the 2.4 is very high and the value for money is very good on the second hand market. So the question posed was, if you could choose between the 2.0 and 2.4 for a car to mostly do short trips in, a lot of people are saying 2.4 for exactly this reason. Yes the 2.0 is a more economical choice, but with the small difference in fuelling and tax across the year, is it worth the saving when you could have a more refined drive?
It's all a question of balance and where your priorities lie.
That said, I bet if you see a 2.0 come up for good money tomorrow and test drive it, you'd love it and buy it. I bet if a 2.4 comes up tomorrow and you test drive it, you'll love it and buy it. The Accord is a cracking car, either way, and both the 2.0 and 2.4 will make great family town cars. The issue here is you're asking 2.0 or 2.4 on a car forum where arguably the majority of members will put ride/drive quality and performance over economy. I wonder what the answer to this question would be on a Prius forum... :lol: