I've never liked loud video game consoles. The original PS4 was notoriously loud and despite my various mods on my unit (like changing the thermal paste, adding a copper shim in between the heatsink and APU, changing the thermal pads, etc.), they weren't satisfactory. But then again, the OG PS4 was a very powerful console in a relatively small box, of course it was going to make noise. Anyways, I longed for a quieter, sleeker, and more power efficient PS4, and Sony heard my prayers by answering with the PS4 Slim. The PS4 Slim is under-appreciated. It's super quiet (even quieter than the XBOX ONE S), and drastically uses a lot less energy compared to the OG. I've always been satisfied with the base PS4's performance and didn't care about the extra power, so the Slim was perfect for me.
The PS4 Slim is almost literally better than the OG PS4 in every way and is the best option for many people who are looking to get a PS4. It's sleeker, smaller, quieter, power efficient, has better Wi-Fi, and is cheaper than the Pro. Yes it lacks an optical out port but there are many ways to circumvent that (TV pass through, HDMI audio splitter, etc.). In comparison the PS3 Slim is also a very quiet console and I'm glad Sony passed the mantle on with the PS4 Slim. These are some of my favourite consoles ever in terms of design.
I don't like the PS4 Pro. I feel that Sony doesn't give justice to the word "Pro," for what they're offering to consumers. The Pro seemed like a rushed console and not well thought out in terms of design and hardware. It should've freaking had a 4K Blu-Ray player but stupid Sony for some dumb, odd reason decided to scrap that.
Oh well, give me a PS4 Pro Slim (which is definitely bound to happen), and I'll buy it.