Almost equal square footage in the cockpit. Gulfstream has 56 sf and Journey has 55 sf. Gulfstream is the heavier and wider of the 2, which will help with ride. No replacement for displacement, so they say. Journey is 1'4" longer along centerline length so not a big difference there. Was just thinking about bridging the waves if they were short intervals like GOM chop, but when I've ever fished Lake Erie, there was no real interval between waves, it was more of a confused sea state.
Between your 2 choices, my personal choice would be the Journey for the little bit more running length and ability to cut the water better than the wider Gulfstream. Boats are all a tradeoff in one aspect or another. Either one would work for you on the Great Lakes.