A new suit should be a little uncomfortable new and dry. It will loosen a bit when wet and also break in with time. The worst thing you can do is buy one that is nice and comfy in the shop. In no time, water will flow through that thing. In a new, good suit, your torso should be completely dry for your first few rides.
As for a drysuit, I had one for years, but I have retired it because I finally spent the money on a good wet suit. You stay almost completely dry in a good 4-3 and it is far more comfortable. That said, I no longer ride on super crappy days because we have so few in Houston. Dallas was a different story.