@visonary--I know from dehydrating fruits myself, the sugar content is usually worse doing this. This is because the water content of the fruit is sucked out and that makes the fruit decrease in size. Basically, you end up eating more rather than less so your intake of sugar increases.
There is a school of thought that agrees with your friend, but most research still shows the banana has a lot of healthy qualities. As with anything, moderation is key.
Bananas have a glycemic load count of 12, just a little higher than an apple. If you decide to eat the chips, try the dehydrated or baked over the fried for the fat count, just be sure to watch your intake.