Both are excellent choices...
The PH II--and its predecessor the PH--has always been rated the best manual marine toilet in its price range (under $500)...you can't go wrong with it. The Cricket has only been on the market a few years, but the diaphragm pump has some definite advantages over any traditional piston/cylinder pump because diaphragms don't have moving parts that wear and need periodic replacement of seals and gaskets. In fact, the "repair kit" is the whole pump assembly except for the housing...and you'd need one about as often as you'd have to replace the entire pump assembly on any other toilet. So I don't think you can go wrong with either choice.
