If it clicks as I type, I'm happy with it. My favorite keyboards, then, are those old keyboards from the 90s that don't even work on modern computers without a PS/2 to USB adapter, since I LOVE the sound they make (managed to snag one from a thrift store for 10 bucks, which I use on my CLI-only Linux work computer running Ubuntu Server 13.10, itself an ex-Windows XP computer from 10 years ago). I've heard the sound of Apple II and IBM 5150 keyboards in videos and REALLY want to try them out at some point (I love old, outdated computers. ^_^ Shame my C64 crashes 30 seconds into startup.

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When it comes to gaming keyboards, I've acquired a Corsair gaming keyboard, can't figure out how to program the 6 programmable keys (nor do I see much need to, since the kinds of games I play use the default keys very well), and while those aren't really points against it but simply my preferred style, THE KEYBOARD DOESN'T WORK ON THE STARTUP BIOS!!!!

If I want to boot into Windows (I'm a Linux/Windows dual-booter) or mess around in the BIOS settings for whatever reason, I literally have to plug another keyboard in to do anything. REALLY frustrating. But beyond that, I haven't really noticed much difference between it and other keyboards I have which aren't designed for gaming. It clicks as I type (^_^), is responsive, the buttons work, it can keep up with my fairly quick typing speed, etc.
BTW, what are mechanical switches? Are those keyboards that attempt to recreate the feel of using an Altair 8800? If so, I want one.