Benifits-
Easier to install, no glue, primer, no need to trench it in (you can pull poly in, but you can also pull in PVC) I use blazing saddle tee's, once in a while just regular saddles.
I would go with poly since you live in Ohio. There are really no disadvantages that I have ever noticed.
Very cheap...I can get a roll or 100' of 1" poly for 20-25.00