The EP82/38 is more parabolic than the CV79/40, the CV has more strength in the lower section (it is rated at 40 whilst the EP at 38) it is not a massive difference though, I've not yet maxed the EP but the CV has as much balls down below as a PE8 rod can have I think. So the actions of the 2 rods are a little different where the CV will tend to fold a little more in the tip section than the EP which will bend through a longer section of the rod. I agree with Mark and Peters comments on lure selection, the 150gm GT2 is the biggest chugger I've tried on the CV which works but as said there are better rods for the job. The EP obviously casts a little further and as it is longer, has a different balance being a bit more tip heavy. The EP is rated 190gm vs CV-200gm on lure weight, I think this ratio right but max ratings not so. Being lighter the CV is easy to work all day and a pleasure to use, the EP marginally heavier but more bendy and will be easier on the angler in the fight if that is what you want, though both are ridiculously user friendly GT rods.
These rods are not specialised they are compromise rods to my mind, and have very similar abilities with popper and stickbait, kind of like a road/trail bike in the motorbike world, you can do both with the right technique but....
If i had to chose 1 it would be the CV, my only negative is the short handle, though i am tall.