Yep, for bass fishing, cable steer is the only way to go. I used to have a powerdrive on my last boat, and while bass fishing, it was a constant fight for boat control. The pedal just isn't ergonomic enough to constantly keep a foot on for boat control while casting.
Now, if you aren't a bass fisherman, I would probably recommend the Terrova. If you do a lot of actual trolling, and don't use a gas motor, that will be where the Terrova shows its stuff. When I longline troll cranks or jigs in the river, the cable steer motor I have now is a pain. I have to be in the front of the boat, with my foot on the pedal at all times. The electric steer motors allow the pedal to be wherever in the boat you may want it, and you can take your foot off without loosing control.
If you are a constant open water fisherman, using multiple lines in rod holders around the boat, and want the trolling motor to just move yourself around, and possibly follow schools of stripers around, the Terrova would be a good choice. Pedal can be in the middle, so you can reach all rods while controlling the boat.
So, if you fish for bass, or something where you are always on the bow deck, casting, or are spider rigging for crappie, go with the Edge. If you troll, or fish multiple rods in open water, go with the Terrova.