Any opinions on which cruise company one should choose for Milford Sound?

Any opinions on whether one should take the 'scenic' cruise or the 'nature' cruise?

Any opinions on best time of day to cruise?

(We will be there in October).

When were were there a couple of years ago, all the boats left from and returned to the same dock. They all cruised up one side of the fiord and back down the other stopping at relatively the same vantage points to view the waterfalls, glaciers and wildlife. It was pretty much like a parade as each boat followed in the other's wake, albiet fairly far apart. As I recall the main difference was the times of departure and length of trip (short vs. long).

The best time to go is after a rain shower, that's when you'll see more water cascading down the sides of the fiord. It's really a spectacular sight. Of course, there's no way to predict if it will rain the day you are visiting and what time of day the rain will come. Don't worry if it doesn't rain before or during your visit, there are plenty of sights to see.

Yelpir, I was waiting to see the reply to your message, as we are going to Milford Sound in late November this year.
We intend to drive from Te Anau (early start of course), then take Real Journey cruise, then SLOWLY drive back to do some of the shorter walks, enroute back to te anau, then stay another night at this town.
Atraveller, I read somewhere that Milford Sound can at times, get buckets of rain, but I have heard the same advice from someone else, that its nice to see when there has been a shower of rain.

Tropo, we have basically the same idea as you. We are spending 2 nights in Te Anau. The first morning early we intend driving straight to Milford Sound and taking an early cruise (probably the two and a half hour one) and then driving slowly back to Te Anau, stopping along the way to enjoy scenery and short walks. The toughest part is going to be to not succumb to the temptation to stop on the way to Milford.
The main difference is that we currently thinking of taking the Red Boat cruise.

A_Traveller, I presume that the longer cruises stop more often and visit more wildlife sights. They also seem to use the smaller boats, I presume in order to get into tighter places.

Yelpir - yes, your assumptions are correct regarding size of boats and number of "stops".