Since the Erie Canal is my home I can actually say with confidence if you want a totally relaxing, no issues, (well almost no issues) stress, wave and crab-pot free cruise definitely consider the canal. The scenery is very nice, the history great, the locks easy to transit, and there are tons of places to tie up for the night essentially free w/ power and water. NYS sunk a ton of $$$ into the canal in the 90s and 2000s so every little canal town has some kind of tie up.
When I speak of the Erie Canal I'm referring to that section from Albany to Buffalo which actually goes under several different names. Some of it follows the original Erie canal but mostly it is a series of "canalized" rivers. The locks are mostly original from the early 1900's from when the New York State Barge Canal was established. Of course one can meander up to Lake Champlain from Albany and then continue up to the St Lawrence, or cut up the Oswego Canal from Three Rivers to Lake Ontario and the 1000 Islands (we're gonna do that this year) or cut down the Cayuga-Seneca Canal to the Finger Lakes (at least two of them) or continue west to Rochester, Buffalo and all the little "port" towns along the original canal route (Spencerport, Brockport, Fairport etc).
Check out www.canals.ny.gov
. Personally we think that the NYS canal system is one of the best kept secrets in the cruising world. If you do decide to check it out purchase the NYS canal cruise guide, it's well worth the $30 and gives you all kinds of advice on bridges, locks, towns, etc. The website has a very good "notice to mariners" section that keeps you up to date on any issues that may impact your travels.
If you head out there give me a shout and we'll meet you on Horseshoe Island for a drink!