Ok, I think we can establish that opps are going to make 4H quite easily. The question is will they bid 5H if pushed? Looks like 5H has a very good chance of making as well. Hence, I would pass the 3H bid! My reasoning is that if the opposition get to 4H, I will bid the standard 4S as expected of me. This will probably yield in a double, but that I can handle. 5H on the other hand, I cannot. So, my stance is to exhaust the options of the opposition before I make my last call.