It depends on your goals,it will run ok as is, but on the lean side, since that is how the ecu is setup from the factory.
Ivans ECU flash adjusts a lot more things than just the mapping, but it doesn't go crazy with the map, so while it's normally good enough, it is not going be tuned for max power, and you would want to add a unit for that.
If you want to tune the bike for max power, and damned fuel mpg, then yes, you will need one of them. If you want to adjust it on the fly, to get better mpg, but switch to power when you want to, I think the pc will let you do dual maps, or the cobra bluetooth version so you can adjust it at will. But the only benifits from these will be more power and lower running temps.
cobra programmer just gives you a few points of adjustments (low, mid, high), the pc lets you change the whole mapping everywhere, and you can get an autotune module for the pc if you don't want to make your own map (might need to change the o2 sensor with a wideband sensor for this to work with the autotuner).