> I don't want a numpad because getting my mouse closer to the center of my desk really helps with RSI for me

Same. I bought a full-sized keyboard with numpad, but I felt it put the mouse too far off to the right. I much prefer the mouse to rest couple of inches from the enter key.

My current keyboard has no number pad for the same reason, but I miss it.

I think my next one will have it on the left side.

You can buy a programmable macropad / keypad (there's a huge range in price). With the most programmable ones (look for "QMK"), you can assign keys to any arbitrary combination or sequence as you choose, and if required make layers, e.g. NumPad layer → IntelliJ shortcut layer → Some game shortcuts.

Just an overview: http://xahlee.info/kbd/programable_keypads.html

I think the only disadvantage is it's a separate thing, so you have two things to push away from you if you don't want to use the keyboard.

> I don't want a numpad because getting my mouse closer to the center of my desk really helps with RSI for me.

Same here. I went with a smaller keyboard for ergonomics. Also, I never use F-keys and rarely use the arrow keys, and there are some "60%" layouts (The [Mass]Drop ALT) that still have the arrow keys. I don't care for the RGB and other blingy crap on these, since I really don't look at the keyboard much anyway.

> 100% keys with no gaps

The purpose of the gaps is orientation: you can feel that you are going to press F4, because there's a gap below and to the right of it.

Sure, that's a nice perk. It's one I'm personally willing to give up for aesthetics and space on the desk. I'm aware it's not the most practical choice :)

Funnily most laptop keyboards get away with no spaces between any keys even when there might be space. Granted, there are more considerations there, but I think convention has a little to do with it too.

I'm surprised how limited the options for 75% keyboards are. I'd think it'd attract a lot of people who went down to TKL.