This is a first-impressions review of the Satechi Slim X3 Bluetooth Backlit Keyboard.I have used every single Apple keyboard design since the original Macintosh in 1984. While some designs were pretty good and others more forgettable, Apple’s (wired) aluminum keyboard (shown in one of my photos) introduced in 2007, with its low height, thin profile, flat plane, square keys, gentle front-to-back slope, and minimal footprint has always been my favorite. Its design was a radical departure from the traditional dome-switch keys (tall, concave keys with a lot of travel) included in wired desktop keyboards of the era. Apple essentially took the chiclet-style keys found on MacBooks of the era, surrounded them with a flat plane of aluminum, and included it as a wired keyboard (including the arrow keys section and the numeric keypad) with desktop Macs. As a touch typist, I was reluctant at first to try the aluminum keyboard … but after 10 minutes of using one, I was immediately hooked, and it became my favorite Apple keyboard design. Burned by the lousy feel of the butterfly key mechanisms introduced in on the 2015 MacBook and 2016 MacBook Pros, I wasn’t willing to try the wireless Magic Keyboard with Numeric Keypad that replaced the wired keyboard in 2017 for desktop Macs — so I held onto Apple’s older wired aluminum keyboards for use with the several Macs that I use at home and work.In early 2021, when Satechi announced the new Slim X3 backlit keyboard (in both wired and wireless versions) with a design that appeared very similar to what I’ve considered Apple’s best wired keyboard — low height, thin profile, flat plane, square keys, gentle front-to-back slope, and minimal footprint, plus the bonus of backlighting — I was willing to give it a try. My early impressions of the tactile feel of the keyboard are very positive; to my fingers, the Satechi Slim X3 feels very comparable to Apple’s wired aluminum keyboard. Surprisingly, as you’ll see in a photo, keys in the main “qwerty” portion of the keyboard are just a tiny bit (perhaps only a couple of millimeters) wider than Apple’s, but the difference is so small that you won’t notice. Overall, the keyboard is actually narrower than Apple’s; Satechi has less separation between the “qwerty,” arrow keys, and numeric keypad portions of the keyboard.The front row of the Slim X3 is at roughly the same height as Apple’s front row. The back row of the Slim X3 is lower in height than Apple’s, but Satechi includes a pair of optional feet; if attached, the back row of the Slim X3 will be higher than Apple’s wired keyboard.The backlighting is a nice feature, and one not available at this writing in Apple’s Magic Keyboard with Numeric Keypad for Macs (as distinct from the Magic Keyboard for iPad or the Magic Keyboard built into MacBooks, which do have backlighting). The backlighting in Satechi’s Slim X3 is almost too effective in that the light leaks from the front and side edges of the keycaps, especially in the row of function keys when viewed from a normal typing angle. (Backlighting on my 2018 MacBook Air and on my Magic Keyboard for iPad both seem to be more contained.) But if Satechi’s keycap design is perhaps less refined than Apple’s in terms of backlighting, it doesn’t bother me — and, of course, the backlighting can be dialed down or turned off.Even though I’m a fan of wired keyboards for use with desktop Macs, I chose the Bluetooth version of the Slim X3 because the wired version has a USB-C connection and I will be using the Slim X3 for the time being with an older iMac that has only USB-A jacks. But I can confirm that pairing the Slim X3 via Bluetooth with a 2012-model iMac was flawless. Because the Slim X3 Bluetooth Backlit Keyboard can also be simultaneously paired with as many as four computers, I also paired it with a 2016 MacBook Pro. Switching between computers, using the function-row Bluetooth 1, 2, 3, and 4 keys at the top of the numeric keypad, works just fine and is quick.Because this is merely a first-impressions review, I can’t speak to the Slim X3 keyboard’s battery life; in fact, it came at least partially charged and I haven’t even charged it yet! If my impressions about durability or anything else are negative after a few months of use, I’ll come back to update this review. But initial impressions of the Satechi Slim X3 Bluetooth Backlit Keyboard are very positive. I’m glad to recommend this product.UPDATE (10 days): Adjusting to this keyboard took no time at all. Although keystrokes feel ever-so-subtly different from Apple's wired aluminum keyboard, the difference hasn't slowed me down. On rare occasions (maybe once or twice a day), keystrokes result in repeated letters on-screen (such as "mm" instead of "m"); I think it's this Satechi keyboard rather than my fingers since I didn't experience this with Apple's wired keyboard, but it doesn't happen often enough for me to be bothered or to reduce my rating.UPDATE (7 months): I continue to be impressed with the feel of this keyboard … but the issue of repeated keystrokes (such as "bb" instead of "b") happens often enough (a couple times daily, perhaps as often as once per hour, on random keys so I don't think it's a manufacturing defect on one or more keys) that I've lowered my rating from 5 stars to 4 stars. Given that this issue doesn't occur with Apple's old wired aluminum keyboard (and I use one of those almost daily on three other Macs), I'm inclined to think that it's a minor design flaw in Satechi's product. Going forward, I will try to pay more attention to which keys see occasional repeats — to confirm my theory that this is a minor design flaw rather than a defect with specific keys on my Satechi Slim X3.