I've recently been looking to replace a Microsoft Sidewinder X4 and had a real tough time meeting my criteria. Geekhack came up a lot in my research

I have 5 criteria and it seems there is nothing suitable: -
Compact (either TKL or the numpad/arrows hybrid. It's uncomfortable to shove a long keyboard left or hold the mouse farther right)
Quiet (I don't mind if this means *horror* membrane or some new MechaMembrane or dampened mechs)
Slidey (Odd word, but it combines Low Profile, non-matt and sloping sided. For gaming I need to slide or roll from key to key)
Anti-ghosting (Again for gaming. 5 keys at least really)
Quality (They can't be breaking or not actuating properly or being weird. Must be wired. Should have lettering that can't scratch off)
One nice-to-have: -
Ergonomic (I like to tilt my board to the right so my gaming WASD grip is angled with my hand, but still need to type messages quickly. Tricky)
So far I've tried 8 boards. 'Gaming' boards are almost ALL mechanical these days and getting the more exotic switched versions nigh on impossible. Want an orange Razor or a silent Cherry? Go fish

The only ones that get near - and you guys will be disgusted - are: -
Keysonic KSK-6001UELX
I know, I know. Ugh. I'm using it right now, though and it's not bad... I 'm ashamed. It is compact, though has a weird layout of the arrow/nav keys, they are all there and the keypad too. It's anti-ghosting which is rare for a cheap keyboard. It's mid-capped and they are not grippy though not glossy. It's membrane so it's quiet but the case is also nicely 'dead' acoustically. It has double injected caps.
The only issue I've had thus far is holding down keys and wiggling that finger can 'unactuate' but sticking a bit of paper inside so it presses down further has fixed it. Yes, it can even be modded somewhat!
Roccat Arvo
Another membrane board! Haven't got one yet - the eBay auction ends in a few hours - they are no longer produced! I imagine it will be much the same as the Keysonic but have better quality and a couple of features like macro keys.
I tried various other keyboards. Mechanical Cherry MX Red and Brown (quite noisy even O ringed). Mecha-membraned Razer (but it was full size and shad an irritating high frequency click).
My highest hope was to take the Cherry MX 3.0 board mid-caps and put them on a Cherry MX Brown switched board with O rings. One of the keys didn't fit and the caps were not the quality I'd hoped.
If you guys don't help me, I'm going to be stuck using a £30 Keysonic until is breaks, then buying another and another (at least they are cheap enough).
Cheers!