I run a fishhawk too when it matters. Right now, it doesn't matter. I haven't gone below 2.8 at Burwell in 6 trips and the fish seem to be able to keep up. When they get fussy, I put the probe out to fine tune but can't really be bothered until the temperatures stabilize and the fish slow down. The speed has more to do with making your Bait run properly than the fish. Spoons don't work well at 1.5 mph and harnesses don't work good at 3.5. Lots of fish are caught at both extremes but your speed needs to suit your bait. In my mind if you troll 3mph instead of 1.5 your cover twice the acreage and present your stuff to twice as many fish so I err on the fast side.