I have a 2007 CR-V with the new R20A engine that's in the 8th gen Accord. (I originally wanted an Accord, but it wasn't big enough for our growing family) Like you, I was worried beforehand that it might feel underpowered, but I can hand on heart say that it has plenty of power. (Bear in mind that the CR-V is heavier than the Accord, so it should have no problems at all in the lighter car.)
The i-VTEC engine is an absolute peach. Honda have a reputation for excellent petrol engines (and diesel of course, but petrol is where they started out), and the R series VTEC engine is simply brilliant, smooth at lower revs, with a lovely growl at higher revs. I find it very addictive to drive- I miss driving it if I haven't been in it for a few days!
I originally planned on buying a diesel, as my previous car was a diesel, but I test drove CR-Vs with both engines, fully expecting not to like the petrol at all. I loved it- it felt so smooth and linear compared to the diesel, which was a bit unnerving at first. It was very sweet. I liked the diesel a lot too, but for my purposes- low annual mileage, there was no good reason to go for it.
One thing I've noticed in nearly all the reviews of the Accord/CR-V is that the petrol engine is almost dismissed out of hand as something to buy if you can't afford the diesel. It's never considered on its own merits. Journalists are a fickle lot- both the diesel and petrol are excellent engines in their own way, and are very closely matched for power, but what the reviews don't tend to tell you is just how good the petrol is. It just has tons of character, is smooth, utterly reliable, and pretty good mpg for a petrol. The power is higher up the rev range than in a diesel, so you need to get used to where to shift as Pepster says- but once you're used to it, it's terrific fun
Bottom line, you need to test drive the car, but I find it has plenty of power. Previous cars have included a Golf 2.0 TDI and a Saab 9-3 lpt turbo 2.0 petrol.
There's a good overview of the engine here:
http://asia.vtec.net/Engines/R20A/index.html
Edit: Forgot to add, I find it perfectly quiet on the motorway, but I suppose it depends what you're used to.
There's another good review of the Accord VTEC here:
http://www.carkeys.co.uk/road_tests/honda/honda_accord_20_ivtec_es_gt_tourer_navi_auto.aspx