I've never ridden a hybrid, but I've ridden a mtb with studded tires, knobby tires, wide semi-slicks (well-worn slightly knobby, flat in the middle) and narrow slicks, and a road bike with standard road tires. For shorter rides I can go almost as fast on my commuter mtb with the semi-slicks as on my road bike but it takes a little more effort and I have to concentrate on riding as aerodynamically as possible, ie. hands close together on the bar and chin low down. This is just too tiring in the long run, so for longer rides I take the road bike as that puts me in the same position with less effort.
The narrow slicks gave such a harsh ride that I've stopped using them. In effect I slowed down to dampen the jarring. But that may be because they're 26 in and hold less air than 28 in road bike/hybrid tires. I hate riding with knobby tires and do so only when I have to, they feel almost as sloooow as my studded ones.
So I think you might get a good speed increase from your hybrid by switching to smooth tires and checking your sitting position, maye you want to swap your stem for a lower one.
Winter riding is much less about badassery and much more about bundle-uppery. - malkin
1995 Kona Cinder Cone commuterFrankenbike/Selle Italia SLR Lady Gel Flow
2008 white Nakamura Summit Custom mtb/Terry Falcon X
2000 Schwinn Fastback Comp road bike/Specialized Jett