Matt,
KH 5 and Victoria 16 didn't come into my criteria because they're under 200 yards but they do fit into a very good group of Australian threes in the 160-180m range (eg, Vic 7/16, KH 5, NSW 2/6, Yarra Yarra 11, RM West 5) which would have all been designed in their day (and for many members today still require) the longest irons in the bag. Some of those holes in the early days would've been nightmarish assignments - YY11. I suppose when the wind blows they become long threes.
Above 180m then it's a case of a great iron shot or, more likely a wood, for your average amateur. RM East 4 just makes the yardage category, but being uphill plays a bit longer.
I tend to think that the long par three for many architects was a bit of an afterthought. Put in where there's a bit of flattish land that's too short for a four but not interesting enough for a short three. And so was produced a long tee shot but fairly uninspiring holes which the average golfers don't like much. Maybe it's because the average golfer knows he's probably not going to hit the green with his tee shot but the second shot is unlikely to be stimulating - in other words, a slog from the tee to a poor green complex.
Mike,
I haven't been to Metro for a long time but I seem to recall that 7 is a bit in that long, flat mould (although I think it is definitely better than most). Newcastle has two long threes which I think fit into that category a bit (although 3 could be reworked into a very good hole). 1 at Yarra Yarra - again, challenging due to it's length but it's not inspriing. There are lots of country courses I can think of with uninspring long threes. I haven't played National Moonah or Ranfurlie so I can't really comment on them but I think the long three is going to become a feature of good modern courses. From all reports, Ellerston has one or two good ones. 11 at Moonah Links isn't too bad either.
I think 14 at Spring Valley is a fantastic long three. I always liked it more than the old fifth, even though most people ranked them the other way around. You rarely see it but a back left pin position makes it one of the toughest threes in Melbourne.
RM East 4, West 16 and Spring Valley 14 all require long but accurate shots to fairly narrow targets which are sit at an angle. They all allow for a some run in the approach. All are well bunkered and the penalty for missing the green can be severe. Each have a no-go zones, but each also have a "bail-out" spot where you can miss the green and still get up and down. In short, they are good holes because, although the average golfer is faced with a challenging tee shot on which he knows the probability of him hitting the green is low, he's forced to think his way around the hole and the incentive is as much about not making 6 than the fact that he's got a slog for a certain 4. And when you make three it gives you enormous satisfaction.