AMOLED Or MIP And Why?

50mm Solar here.  I got it for looks, battery life and the improved contrasty screen compared to my 2X

I have both of them, and AMOLED is a superior watch. I do not care much about the display - each of them has its advantages and disadvantages, but the AMOLED model is much more responsive, and faster - no delays, saving activities or loading courses instantly (while at Solar it takes seconds to tens of seconds), and it also mounts as an MTP drive on a PC within a few seconds, while Solar usually needs tens of seconds. The much bigger memory is important to me too.

Besides that, AMOLED Instinct has some features not available on the Solar model (for example locking the compass heading, viewing photos in messages, large fonts, workout animations and muscle maps,...), and I suspect that the difference may grow in future, due to the limited memory and lower CPU speed of the Solar model.

And then, despite the specifications, the battery life of the AMOLED model is in fact much better than at Solar (it might perhaps change slightly in summer with more exposure to the Sun, but currently I have to charge the Solar model more often than the Amoled watch).

I think you already posted about the sounds in another thread, and I thought I answered there - the beeps work all right for me.

They work fine.

With the same settings and the same use, it is not possible for the AMOLED to work longer. The screen itself consumes a lot of energy.

I do not use the Always-On-Display option on the AMOLED model. I have no need for it, and still can use the watch comfortably with just the wrist gesture. If you need the watch display lighting 24/7, do not buy AMOLED. 

well, I have an 45mm AMOLED and I have Always-On-Display (with wrist gesture)

Brightness LOW

Pulse Ox while I sleep.
I turned Messages notification OFF (I end up checking my phone anyway) That consume battery more than other things.
I use GPS for about 1h 15min per day and track exercises (gym) for 1h, 4 days a week
The battery last for a week.
That is pretty impressive in my opinion. 

Of course, turning some settings off will make the battery last longer, but I want to use all the options.

Having a reminder to charge my watch on Fridays while in the office , matches my routine very well too.

well, all those reasons are 100% valid for me too.
If you are going to buy something that you will be looking at, it better looks the way you like it.
I also discarded the Solar based on the screen resolution. I had a VivioActive 4 and the resolution was better than the solar.
Battery last more than I expected too, so win as well. 

Jonathan said:

I turned Messages notification OFF (I end up checking my phone anyway) That consume battery more than other things.

Not really. I am currently testing the battery life of an Instinct 3 AMOLED 45mm, with notifications enabled (AOD off), and after 34 days it has still 36% of battery remaining, despite getting around a dozen of notifications daily. It extrapolates to 51 days without charging (specs claim 18 days only).

The biggest battery consumers are the GPS, PulseOx, and then the display. Possibly some of CIQ watchfaces and apps too. BT can add up considerably only if there is a connectivity problem causing continuous reconnection attempts, or in case of transmitting huge data files with failing transfer. Notifications are negligible, unless you get high hundreds of them daily.