The K70 MK.2 Low Profile retains Corsair's signature "floating keys" look, but the keycaps have been significantly slimmed down. The Low Profile switches wouldn't be able to operate properly with full-size Cherry keycaps secured onto the switch stems. Besides the lowered height, the keycaps are identical to standard Cherry profile switches. The tops are shaped the same, and they are compatible with Cherry MX stems, unlike Cherry's previous low profile switches. As usual, the keycaps are made of thin ABS plastic. I'd like to see Corsair take the lead here and help move the industry standard to double-shot ABS or PBT keycaps.
Cherry MX Low Profile switches, or LP switches for short, have a total travel distance of 3.2 mm rather than the usual 4 mm. The actuation distance is also shortened. LP Reds have an actuation distance of 1.2 mm, as opposed to the 2-mm actuation distance of standard MX Red switches. However, Cherry has made special LP switches exclusively for Corsair called Low Profile Speed switches. LP Speeds have to travel only 1 mm to actuate, although they retain the overall 3.2-mm actuation distance of LP Reds.
Corsair uses the Rapidfire name to denote keyboards outfitted with Speed switches, and this particular K70 MK.2 happens to be sporting that fancy title. I was really looking forward to trying out LP Speeds because I'm a fan of the Speed Silvers in Corsair's standard Rapidfire keyboards. Speed Silvers fixed my primary problem with Reds: a sensation that my fingers are wading through a swamp while typing. The shorter travel distance and crisp bottoming-out of Speed Silvers make them feel snappy rather than sloppy.
Unfortunately, I was let down by LP Speeds. The shorter actuation distance and total travel distance make them feel less swampy than standard Reds, but the sloshy feeling remains. LP Speeds have cushioned bottoms, similar to Reds, whereas Speed Silvers let the key-cap-and-switch assembly clack as they bottom out. You can distinctly hear the difference in the sound clips below. The harsh clack of Speed Silvers provides the satisfactory tactile feedback that most linear switches lack.
Consequently, my typing speed and accuracy has been worse than usual while typing on these LP Speeds. Writing this review on these switches has been something of a slog. I've mostly grown used to LP Speeds for gaming, but I'd still rather be using Speed Silvers.
Even still, LP Speeds do have a couple benefits. The reduced travel and actuation distance is definitely a plus for quick key presses. Other switch manufacturers have been moving to lower-profile switches, and it's good to see Cherry produce some of its own in an age where the laptop keyboard reigns supreme. LP switches are also much more stable in comparison to standard Cherry MX switches. Most full-height Cherry switches wobble, in my experience, but LP switches are more resistant to jiggling around at rest than even some of the high-quality low-profile competition.
If you're already a fan of standard Reds, I see no reason not to switch to LP Speeds or Reds if you want a shorter key height for a trimmer-looking keyboard. However, if you like Speed Silvers, LP Speeds are not a better or even comparable alternative. Speed Silvers already have a a total travel distance of 3.4 mm and an actuation distance of 1.2 mm, so the LP Speeds don't go perceptibly faster even as they lose some height. I will maintain my position that Speed Silvers are the best Cherry switches for gaming. As always, I highly suggest trying out a given switch in person before buying a keyboard loaded with them.
AquaKeyTest indicates that the K70 MK.2 has N-key rollover, so gamers won't have to worry about conflicting inputs when pressing multiple keys at once.
Corsair's peripheral software, now going under the name iCUE, has evolved over time, and while the changes have occasionally been a mixed bag, I think iCUE is pretty good in its current form. As I mentioned in my review of the Strafe MK.2, iCUE is overly cluttered upon start up, but once you select the device you'd like to configure, most of that clutter goes away. I would like to see the configurable options for each device collapsed into just a few less tabs and sub-menus, but the overall aesthetic of the software has improved significantly. It is considerably easier on the eyes than in the past and doesn't hamper usability. Aesthetics and usability aside, iCUE is quite powerful for configuring profiles, macros, and lighting effects.