Totally Agree it is way more than fine for HDV
Depending on software it is quite decent even for AVCHD
Some software are just not as efficient with resources as others
Adobe Premiere Elements ( and Pro) run better with better hardware
If you have Nero Vision ( full version) you can get some AVCHD clips and see how you get on with them.
You have to draw the line somewhere though. A well set up i7 system will fly but your system looks as if it will work fine . All boils down to what you consider as " more efficiently"