Dragon I believe the reason behind your lag while using action has to do with file size and writing and playing from the same hard drive. From the look of your specs I'm assuming it's a laptop. I don't know if recording to an external hard drive would help or not because of the transfer rate. Bandi has a very small compared to the others.
I ran a little test last night between fraps and action. I recorded a 10 minute video in Iron Front with a massive 100 AI battle. Action's 10 minute file size was 4.24Gigs and the Fraps 10 video came in at 12.5Gigs. There was very little difference in quality, some but not enough to justify me giving up action.
If you have an external hard drive you can give that a go to see if it helps but I think the transfer rate will be the bottleneck. This is all just my opinion and experience.
EDIT: Found a nice video showing the differences