Hey Bob!
Welcome. I have the PT175 (MY 2002) with a 40hp 2 stroke (MY 2003). I take mine out on the Potomac river near the DC area and the creeks further south. The boat handles fine up to waves with white caps just starting to show. It can handle more, but I don't like pushing it. I like to think I have a very healthy respect for the power of water.
As a first time boat owner (but not first time operator), I've been very happy with the set up. My top speed is a bit less than Treps in that I max out at 25 mph. Of course I also installed a Mac's River Runner prop and skeg guard that took about 2 to 3mph off my top end. Small price to pay to protect the lower end from the shallow parts of the Potomac river. Sometimes I wish I had gotten the bigger motor (like an Etec 75 hp!!). But I digress.
Good advice from the posters above. Most important, look at YOUR needs and decide what's best for YOU. Me, I like the PT175 because of its ease of handling, durability (I don't mind beaching on concrete ramps or the occasional bump up against the dock), and economy of both purchase price and operation. It works where I fish.
Good luck!