I just downloaded the latest update from Asobo, and want to put out a warning to everyone who hasn't done this yet: there may be a glitch that causes one of the packages to crash and restart it's download multiple times. I wasn't paying attention, and let the download - which was supposed to be 41 gB - proceed unattended while we were eating dinner. By the time I got back to my computer four hours later, the updater had consumed 650 gB, which is 1/2 of my monthly Comcast data cap! So my advice to everyone: NEVER leave MSFS unattended while it is downloading an update, and keep an eye on the process, to make sure you catch a glitch like this before it can consume a huge chunk of your data cap.

There are some aircraft upgrades in this package. The Cessna 172 and the Cub Crafter now come with optional floats or skis. I played with C-172 float plane for a while and noticed a few things:
1. There are FINALLY (a full year after first release!) water effects for the sea planes. When you operate the C-172 on water, there is spray, and the floats leave a wake. But the effect doesn't look quite as nice as it did in FSX. The wake dissipates too quickly, and the "spray" doesn't look like it actually goes up into the air at all, which it should, at least 2 or 3 feet.
2. The behavior (flight model) of the C-172 doesn't feel quite right when it touches down or takes off on water. The drag coefficient of the floats may be too low - the plane takes off too easily from water, especially when loaded to maximum weight. And it will take off at max gross weight even with zero flaps, which shouldn't be possible in the real plane, I think.
3. It bounces when touching the water, as if the plane was landing on tundra tires on a hard surface. This seems completely unrealistic. When a floatplane or flying boat touches down on water, there is an immediate drag effect and adhesion between the water and the floats or hull that slows the plane rapidly. It certainly should not bounce back up.
4. The landing gear aren't animated - i.e., they don't extend/retract into and out of the floats when toggled with the "G" key. This is very disorienting when flying in External Camera or Showcase view modes, especially when making an approach to a water landing, and there are the gear hanging down. There is a voice prompt that tells you whether the gear are configured for water or runway landings, but if voice prompts are disabled, you won't hear them. This could all too easily lead to landing on a runway with the gear up [Crash!], if you were flying in external camera view, and saw the gear as "down".
5. This update adds a bunch of new features and modes that are probably meant for PlayStation users, but that interfere with Windows PC functionality. Most annoying is that these modes are the "default", and that you will suddenly find that you can't push buttons or turn knobs on the instrument panel with the mouse. To fix this, you have to go to Options > General Options > Accessibility, and change the Cockpit Interaction System to “Legacy”. It would have been nice if Asobo had included coding in this update that checks what kind of computer it is being installed on, and not set the defaults to PlayStation mode when the update is being installed on a Windows PC. This drove me nuts for a couple of hours before I finally found a posting on the official MSFS forum explaining how to fix this problem.

Playstation users? Huh?

The water rudders don't work, either...by by keyboard, or by the water rudder handle at the floor console. They don't deploy or retract. 

39 minutes ago, lgcharlot said:

The landing gear aren't animated - i.e., they don't extend/retract into and out of the floats when toggled with the "G" key.

This could be a conflict with a mod in the Community folder.

In my case: the Robert Young Bonanza mod..

Removing the mod did the trick.

5 minutes ago, Sesquashtoo said:

The water rudders don't work, either...by by keyboard, or by the water rudder handle at the floor console. They don't deploy or retract. 

See my response above..

7 minutes ago, Sesquashtoo said:

The water rudders don't work, either...by by keyboard, or by the water rudder handle at the floor console. They don't deploy or retract. 

In my case it was the Bonanza mod too causing that issue. if you have it try uninstalling.