I have used both and prefer the rope.
The wire is good for large areas if the proper wire is used and you have the tools to work with it. If you cheat even a little bit on installation, it is horrible to work with and maintain. I had a horse run full tilt into a 3 strand wire fence and it held, however, the horse bounced right off it and flipped up and completely over the fence landing on her back. She ended up with some wire burns and a lot of soreness, but no major cuts. I don't know if it would have been any better if the fence had broken or given to the impact.
Now, I use a white 3/8" nautical grade Poly-rope with 6 strand conduction wire woven through it. I really like it because it is strong, visible, easy to work with and easy to maintain. It looks good too. Like the wire however, you must install it correctly with proper tension and connectors. The tools required are minimal and it is very easy to work with. I use treated wood posts with screw in insulators and they work great. In two years with temps ranging from -40 to +35 celcius, wind, rain, snow, hail, etc, I've not had to do any repairs. The only thing I have noticed is the rope stretches a bit when it's cold, so I watch the tension in the winter. I also keep some extra rope and step in posts on hand for cross-fencing. This way I can rotate grazing within my pastures in any configuration with minimal set up. We do electrify the top wire about 25% of the time and the horses don't ever offer to challenge it. I think the rope has a 10 year warranty.