as far as those 5 go, the things i would find acceptable are MMP with PV electorate votes and no 5% threshold, or alternatively STV with either a single nationwide "multi seat constituency" or at most 4 or 5 huge electorates (so that the south island and Auckland become 1 electorate each).
What i think would be better is the Most Open List. You get your party vote, you get your proportionality, you get to vote for your local candidate if you wish, but you're not limited to voting for the one and only (your party) candidate in your "electorate". You can vote for anyone on your favorite party's list, be it the preferred local candidate, another local candidate you like better, a candidate from a neighboring electorate or even someone from the other end of the country if you feel they represent you better.
And the icing on the cake for people that follow politics closely, you can if you want to rank everyone on the list yourself, which means you can effectively "un-vote" someone you don't like, all without losing your party vote and proportionality.
And yet it is not on the list of finalists, despite no one even asking whether there might be a better option out there. Instead we have what feel like the same hand picked straw men to make the government's favorite system look good especially when the info given about the options is whatever they could pull off wikipedia in 5 minutes.
Have a look at the descriptions of the 5 systems on www.elections.org.nz:
Some STV systems[...] Other STV systems[...] Yet another alternative[...]
What do i have against MMP FPP STV PV and SM?
MMP - list members no one wants, and how important the party organizations become, being 100% in control of the party list. Worries about "wasted votes" give minor parties a huge disadvantage - both in electorate (2 horse race) and party votes (5% threshold). Not proportional in the case of overhangs.
FPP - not proportional, nationwide (not concentrated in few areas) minor parties have no chance (Greens, NZ 1st, historically Social Credit). Worries about "wasted votes" give minor parties a huge disadvantage.
STV - only proportional within electorates, so a party needs to get up to around 10% of the vote before they start getting MPs, so this and worries about "wasted votes" give minor parties a huge disadvantage. Depending on how 2nd votes are transferred, this either results in elections depending on chance (random selection of winning candidates surplus voters) or calculating fractions of votes quickly descending into an obscenely complicated process of re-counting and calculating fractions. Multi seat constituencies will be about 3 times as large as current electorates (in rural areas) so some areas will be without adequate local representation e.g. the west coast might plausibly end up with 3 MPs all based in Nelson and Blenheim (Although currently it would be entirely plausible for the MP to be based in Motueka)
PV - not proportional, nationwide (not concentrated in few areas) minor parties have no chance (Greens, NZ 1st, historically Social Credit).
SM - not proportional, minor parties disadvantaged in electorate seats. Party organizations become too important, being 100% in control of the party list.
Update:
Some people are talking about one change that might be made to MMP if we keep it is to open the lists. This would be great, but i should specify that my vision of the Most Open List was to abolish electorates altogether and let voters use their list rankings to ensure local representation.
I also want to point out that current "independent"candidates would be free to run as a 1 man party, and in this case using the current Saint-Lague formula and assuming 2.4 million votes, independents would only need about 10,000 local votes to get their 1 and only list candidate into parliament, about the same number it takes for an independent to win an electorate currently.
My favorite part about this is that those 10,000 votes don't have to all come from within an arbitrarily delineated "electorate" but can come from anyone who feels represented by the independent. An example is if someone from Queenstown-Lakes district wants to run as local representation, he could have 7000 votes from Queenstown and 3000 votes from Wanaka. Currently these towns are split by an artificial electorate boundary.
This would also work for Maori electorates. If Hone Harawira got kicked out of the Maori Party but can still get 10,000 votes from Maori in Te Tai Tokerau, he can go to parliament and represent Maori in Te Tai Tokerau. Even better, this still wouldn't stop Maori Party voters ranking their local candidate at the top of the list and getting a Maori Party MP for Te Tai Tokerau too.
