The Corsair M55 RGB Pro is an ambidextrous, fully symmetrical gaming mouse, so it can be an ideal choice for both left-handed and right-handed gamers. It's medium-sized, but rather tall for its overall dimensions, making it a suitable choice for pretty much all gripping styles, but in my opinion, claw and palm grippers would find it best. It features some really good surface materials; the top cover has a slightly rough, matte surface treatment, while the sides are heavily textured and most probably coated with a hard rubber. The whole mouse felt just right in my hands.

As for build quality, it's nearly perfect, with only one issue I could detect: the scroll wheel can rattle around in its place because its axle doesn't perfectly fit into the encoder's slot. Hopefully, not all units are affected as the mouse is very solid overall otherwise. The M55 weighs approximately 89 grams with a little bit of cable, which means it's a well-balanced model; it cannot be called lightweight or heavy, either.

There are a total of eight fully programmable buttons on the M55 RGB Pro. The main ones are decent, but not perfect. They feel a bit stiff and definitely aren't the most tactile buttons I've tried so far, but aren't mushy either. They have negligible post-travel after actuation. They use Omron D2FC-F-K main switches with a nominal lifespan of 50 million clicks. Scrolling is light, and apart from its rattling, it could be called pretty good. As for the side buttons, they are just great, snappy and tactile. The middle click is also very good; it's pretty light and not tiring to use excessively. The CPI button is decent as well; it's clicky, tactile, and spammable.

Moving on to the sensor, the M55 RGB Pro features a PixArt PAW3327, which is a mid-tier tracking unit. To be fair, if it didn't have this high of a lift-off distance, I would be happy to call it a fantastic sensor. It's raw, snappy, and has a high perfect control speed. It starts jittering earlier than most top optical sensors, though, and "only" has a maximum CPI of 6,200, which is doubled by some software interpolation, so you can actually set it up to 12,400, which I'd advise against because there's some smoothing at around 4,500 CPI.

Mouse feet are objectively good on the M55—smooth and of medium friction. They have some well-rounded contact edges, which means they do not feel scratchy. Unfortunately, there are no replacements in the box, which is quite a letdown. As for the cable, it's pretty dreadful if you're used to a light, flexible one. This one is thick and stiff and tends to generate a lot of drag resistance. It's 1.8 meters long, which should be enough for most users.

Settings can be adjusted in iCUE, Corsair's all-in-one software. As I've said numerous times in my previous reviews, it's good, albeit not resource-friendly. A lot of customization is available as pretty much nothing is left out: profiles, macros, pointer settings—it's all there and pretty easily accessible. RGB lighting is of course present as well, as the rear Corsair logo lights up according to the settings, of which there are many. There are a ton of different effects, and you can customize some of them to your liking, too. The colors are vivid, the lighting is bright, and the effects transition nicely and smoothly.

At $39.99, this mouse has a ton of possible competitors; however, not many are fully ambidextrous. This one features a good sensors, decent buttons, and some really nice materials, but there is room for improvement. The overly stiff cable and the QC issue on the scroll wheel mess up its overall image as I would happily call the M55 RGB Pro an Editor's Choice otherwise. While it has these two small issues, the cable might not be a problem for most users (a bungee or just a piece of tape can definitely help), and the scroll wheel's rattling might not affect all units. Considering everything, I would wholeheartedly recommend the M55 RGB Pro to anyone who finds the shape and specifications suitable for their needs, as it is still a solid choice in its price range.