So anyone notice each party is ferociously advancing the position that best serves their own interests?

The Conservatives raise lots of  money and profit from the "Split-the-Left' vote. So they want  a referendum  (something they didn't give a hoot about when they were in power and making their own quite dramatic changes) as they secretly hope it will be defeated. And obviously they aren't interested in the 'per-vote' subsidy. 

The NDP has proposed a complicated 'proportional vote' system (if they were more honest, they'd just demand a straight up allocation of seats based on percentage vote) as, obviously, they would do best under that system. And they'd be happy to get a subsidy again. 

Similarly for the Block and Greens.

The Liberals prefer a ranked ballot (again, since they'd do best) and .... Well, they originally introduced the subsidy ... I guess we'll see on that one.

Regardless, what ever they do, if it takes more that 2 minutes to explain, it is too complicated.