I want to share review and comparison for the following 3 keyboards:
Keychron V1 - 75% with exploded Function keys - No knob - Keychron K Pro red linear switches.
Epomaker TH80 - 75% with exploded Function keys - With knob - Gateron Pro brown switches. (Note this is old Standard version; not Pro version)
Glorious GMMK TKL - 85% - Gateron brown switches.
Summary
If I can mix and choose the highlights of all these keyboards, I would go with:
Keychron keyboard (function)
Epomaker TH80 feature (wired and wireless function)
Brown switches (personal preference)
Epomaker TH80's MDA profile (personal preference)
GMMK TKL's styling (personal perference).
I bought these keyboards as complete kit. As doing customized build cost much more. And because I'm a cheap skate.
I will start with more functional features and then go toward looks/style.
Build quality and sound
Keychron V1 is the best
Epomaker TH80 is close second
GMMK TKL is worst
This is in terms of with weight, solid feel, thud, and less empty or echo sound. Both V1 and TH80 are have plastic exterior. V1 feels like it has more dampening. Typing sounds more deep thud. TH80 is very close to V1, but feels and sounds less dampening. GMMK TKL case has some metal mixed with plastic. However, GMMK weighs the least and has most hollow sound.
Key Profile
Epomaker TH80 MDA
Keychron V1 OSA
GMMK TKL OEM.
I really like Epomaker TH80's MDA. It has large fat surface with rounded corners. MDA also has this curved or sculpt shape from top to bottom rows. I don't feel the ergonomic difference in performance, but it just looks cool.
OEM and OSA have similar profile. Difference is in the corner shape. OEM has square/rectangular corners. OSA has rounded corners. In terms of looks, OSA looks better to me, because OEM is just too generic and square looking. However, OSA has the smallest top surface area. It probably doesn't matter in actual typing performance, but the look and feel of the OSA top surface is too small.
Functionality/Features
All 3 keyboards have hot swappable switches. So same there.
Epomaker TH80's advantage is Windows/Mac compatible; wireless feature thru either bluetooth or 2.4Ghz dongle; and metal volume knob. The wireless does have some quirks that I posted about on reddit. But if you can live with weird implementation, the wireless does work. (https://www.reddit.com/r/BudgetKeebs/comments/w4tq4a/epomaker_th80_quirks/).
Keychron V1's advantage Windows/Mac compatible; exploded arrow keys at lower right. Keychron V1 does have option for knob, but the one I got does not have knob.
Glorious GMMK TKL advantage is LED to provide status of CAPSLOCK and Windows key. TKL, so keyboard is longer with more keys.
Switches
This is personal preferences. I cannot really compare Keychron's K vs Gateron's switches, because Keychron is red linear and Gateron is brown (clicky with low force). I just like the feedback of clicky brown switches.
Keycaps Material
Keychron V1 and Epomaker TH80 use PBT
Glorious GMMK TKL use doubleshot ABS
This has both functionality, design choice, and styling impact. Keycap material, key legend, and LED orientation on switches are all dependent.
I like PBT, because it feels heavier and more solid. And supposedly the surface will last longer. In comparison, ABS feels lighter. And supposedly over time, the surface can wear out; matte feel will change into glossy/sheen look. Hasn't happened on GMMK TKL yet, but I have old keyboards with ABS that has this issue, particularly on heavily used keys like WASD and where the fingers rest on: ASDF and JKL;.
Key's alpha-numberic legend on PBT is printed. Doubleshot ABS has shine-thru legend; so LED will light up the key legend. Depends if you prefer function or style.
LED on Switches
LED physical orientation is due to design choice related to the keycaps. Keychron V1 and Epomaker TH80 have south facing LED, because keycaps are PBT and do not shine thru. The LED at bottom will let more light come around the keys (or in the gaps between the keys) reach the user. In contrast, GMMK's LED is north facing, so LED is aligned with key legend.
The overall effect is that V1 and TH80 LED are more background colors, whereas GMMK TKL's shine-thru can provide very specific and distinct LED patterns.
As for the LED colors, Epomaker's TH80 seems to have less hue. LED cannot show pure yellow color; yellow/orange tend to be mixed.
Software
Keychron V1 QMK/VIA compatible
Glorious GMMK TKL
Epomaker TH80
Keychron V1 is QMK/VIA compatible. I am actually not familiar with this, as I just got the Keychron. My kid is using this keyboard. So depending on the ask, I might or might not look into the VIA software. I assume VIA is most customizable.
GMMK has very professional looking software that is very easy to use.
Epomaker TH80 now has software that is actually usable; not super intuitive so need some trial and error to figure it out. There is no help or documentation at all.
All 3 allows re-mapping, disabling of keys and macros.
As for customized LED, I like to make customized LED lighting by key functions, for different games. For instance, WASD having different color for FPS and adventure games. Customized LED by key is most functional with GMMK TKL's double-shot ABS with shine-thru legends.
Both GMMK and Epomaker have software that allows customize LED. Right off the bat, I don't know how difficult (or if it is even possible) to make customized LED lighting using VIA.
Styling
Glorious GMMK TKL
Keychron V1
Epomaker TH80
Again, depends on your taste. To me, GMMK TKL looks the nicest. It has no edge or border on the keyboard; with aluminum edging. In term of shape, both Keychron V1 and Epomaker TH80 look similar. Obviously color tone is quite different, as Keychron is dark whereas Epomaker is light. I prefer the dark shade on Keychron V1 over Epomaker's TH80.
I value function over style. So Epomaker TH80's is my keyboard of choice among these three.