Buy 0 degree, and if you don’t like it you can use some separate bump-ons to raise it to your desired angle.
Bonus: use corks and have a reason to buy & drink some wine while contemplating why you spend so much money on keyboards.
They also can be shaped nicely with a cutter and go well with PC 
It really depends on how your sitting / standing, the height of your chair, and or the height of your desk.
From my understanding of ergonomics, you want a negative slant, if your forearms are at a downward angle, if your arms are level with the ground, you want a flat keyboard, and if your forearms are pointing up, you want a positive angle.
Essentially, you wan the angle of the keyboard, to allow for your wrists to be straight
Wait, people use desks that make their hands go up? Why would you do that to yourself?
Never tested 0 degree myself.
I use 5 degree in my current keyboard and it is comfortable to use (it is more or less the angle of a Filco while not using the raiser feets).
Have another keyboard with 3 degree but I find the one with 5 degree more comfy to use personnally. But the 5 degree one is using MT3 keycaps while the 3 degree one is using SA caps(a tad taller).
Also the thickness/height of the keyboard plays a role in the comfort IMO, the less the better.
As you see it is a matter of preference, keyboard thickness, caps height, …
It goes back to the days of type writers, because of how bulky the mechanisms were. some of the original keyboards, were built with the same foot print and in the case of the IBM 5251, they even had solenoids, to make them as loud as type writers.
IT experience: Most of my users say they want the keyboard angled up, so they can see the letters… they are going to have wrist problems later in life…
I have my hands flat to the desk.
O well… Seems I will be going the 0 degree route.
I definitely prefer 0 angle as well. I think when you see people turn the space bar around, the angle is part of the reason they do it. The angle encourages the typist to cock the wrist back, but when you do, hitting that sharp side of the space bar doesn’t feel good after typing all day.
It’s great that 0 angle is even an option, you don’t see that too often.
Just for fun, here’s a super nerdy academic study on the topic. 
Just when I thought I made my decision you come and stir things up 
I think thumb shape, length, and angle (Possibly a factor of the keyboard tilt.) of attack play into that. I’ve always flipped my space bars when possible, because I don’t like the edge of the space bar digging into my thumb, especially when gaming.
I did not get enough sleep last night, to fully comprehend that article. Will have to check it on when I’m not on call and my phone hasn’t been abused.
IT observation: I completely forgot about our transcriptionists, as they primarily work out of the office these days. Each one is very particular about their posture, keyboard positioning, and a couple of them are very particular about the keyboards that they use.
Two of the transcriptionists use your standard Dell membrane keyboard. Two of them use Microsoft Natural Ergonomic keyboards. The two that use MNE keyboards swear by them, and hate using standard boards, nor are they a fan of the new ergonomic keyboards with chicklet style keys.
I showed one of the transcriptionists that uses a MNE a few split mechanical options a while ago. They did get here excited and she also like d the old keyboard that I had ad the office (MX Blues), but anything non standard layout wise and not full-sized is a no go for her. Too many short cuts depend on having a number pad and from my experience ASCII codes don’t work with a stand alone number pad,
I think thumb shape, length, and angle (Possibly a factor of the keyboard tilt.) of attack play into that. I’ve always flipped my space bars when possible, because I don’t like the edge of the space bar digging into my thumb, especially when gaming.
Yep, I’m the same way. I did that on my topre boards (HHKB and Leapold). Actually, I didn’t have to do it on my realforce board because it has the extension legs that come out that can fold in so the board lays flat on my desk instead of an angle. That’s one of major reasons why I will likely be selling off my other HHKB in the future. That, and the fact that I switched to ortholinear a few years ago.
I’m very much for 0 angle or negative angle, and as flat as possible. I actually couldn’t use any “regular” mechanical keyboards, because they were all too high, and a wrist rest makes the angle all wrong. I used the Logitech UltraX for years until it fell apart. Now that I discovered the choc switches, I’m a happy camper, with boards that are basically the PCB lying flat on the desk.
5 degree angle is too flat for me, I much prefer 7 or even 8 degree typing angle.
And I’m using wrist rest.
Also, inverted spacebar (on cherry profile keycaps).
I also got this board, but I got the 5deg option. My issue was which color to buy, not which angle. Lol
Poly + fr4 will be my choice.
That’s an interesting preference
I couldn’t decide so I got poly and space grey. 
there goes my budget for a while…
To each his own 
Many of the supposedly ergonomic things just don’t work too well for me…
Your setup may be ergonomic, it really depends on the whole picture. How are you sitting/ standing. and how are your arms positioned in relationship to your position,
Two of the most comfortable keyboards I’ve used have been the Tex Shinobi and the SteelSeries 7G with it’s included wrist wrest, both in their flattest position, which still have a slight degree of tilt, but I also position my arm wrests, so my arms are slightly extended out and angled up ever so slightly.
Apart from was said above, I think tall sculptured keycap profiles like SA, even more benefit from low or absent keyboard angles.
This also explains why I still like the low-angled Magicforce68 keyboards with AFSA keycaps.
Could it be that many of nowadays mechanical keyboards with a fixed angle are designed for use with Cherry profile in mind?
