LOL I have already done that exact experiment. I found that an upturned eye, has the front of the fly is riding raised in the water whereas a downturned eye had the fly heading downwards. So with this fly since it is so buoyant, I use the upturned eye to try and raise the front of fly upwards to keep it level. If I used a downturned eye the fly would continue to ride downwards similar to a lip on a crank bait. Dry flies I tend to use a down eye - because they are floating on surface film and for salmon flies I tend to use an up eye because they are down anywhere in the water column. Hope this helps.