I've owned two(1).
The first was a Filco Majestouch Otaku, blue cherry switches, very loud and clicky. Very very comfortable and satisfying for me to use. Started suffering from switch bouncing after only a few years, also even while the keycaps were blank, they were apparantly coated with something, which was worn down from usage. With better firmware, I'd recommend, but it's no longer in production.<p>My current keyboard, I've had for 6 years, it's from WASDkeyboards.com and it still performs very satisfyingly.
It is a standard ISO layout with red cherry switches. While the switches themselves do no click, it is still satisfying to use, and less hard on my fingers (when you've learned not to rest your fingers on the keys, as they are very light). I had one switch become defective within a month, but WASD sent me two new replacements and noted that I had opted to do the repair myself and have it still be covered by warranty! (VERY NICE!). Again I opted for blank keys, and again there is apparantly still some coating on top of them that is worn down.. Some of the keycaps are now more concave from plastic being physically worn away, but new keycaps can be obtained.
I'm very happy with both the style, function and especially quality of this keyboard, and it is highly worth the price to me, as it's lasted longer than any other keyboard I've owned, and continues to be an absolute pleasure to use..<p>At work I use some random dell rubberdome thing, that's fine too, just not as satisfying to use.<p>I don't think any of the keyboards have boosted my productivity, if they work, have no stuck or bouncing keys and their layout is usable for me, then I'm limited by brain speed, not finger speed.<p>(1) I also had a steelseries g6v2 but it broke so quickly and had other issues, it's not worth mentioning. I've also used an IBM model M for a year to annoy someone at work, but it was not pleasant for me, even if it's supposed to be the holy grail, I own several, for my old computers, and they belong there in my opinion.