I want to headline this review first with a buyer beware; if you are thinking of buying this or already have bought it, make sure your mouse does not have creaky clicks. You can tell by clicking the button, it'll feel a bit mushy and make a creaky sound that radiates throughout the mouse. This is not normal. I replaced my first Viper Ultimate because it had those issues, and I'm happy to say the second one that I just received seems to be good for now.
Second thing, Razer really needs to add more functionality to the dock. Yes, the dock and the mouse syncs with Razer Synapse when they are apart and it makes your desk setup look cool. However, you CANNOT change the colors of the dock and mouse while they are charging together. On one hand, its nice to see that you can tell the battery level through the dock/mouse glowing red/yellow/green, but because of the long battery life and quick charging times, I'd like them to make it so I can change the color of the dock while my mouse is charging. Having the color of the dock and the mouse out of my control sucks and its something I hope they address in a future update.
The fit of the mouse feels nice to my hand (Size M). Battery life is long. Charging is quick. When the mouse is off, the light turns off without a white outline so the mouse appears all black which is pretty cool. 2 buttons on each side of the mouse which is useful for some games. Not an infinite scroll wheel. Lightweight. Cool design.
Don't buy this at full price ($200) if you can, wait for a sale and pick it up for less (~$160).
EDIT: 5 -> 2 Stars. My replacement Viper Ultimate came in and at first it was perfect. 2 days later the creakiness crept in on the right button. I notice this every time I click down on it. You will notice it through the post-travel of the button, meaning that after you pass the threshold of the mouse registering your click, you are able to go a bit further which makes a grindy, creaky, and squeaky noise. In addition to this, the buttons will feel extremely mushy.
EDIT 2: 2 -> 1 Star. Amazon issued me a partial refund, meaning I got this mouse around ~110 CAD from 200 CAD. I thought I could tolerate it, but the button actually got worse. It feels more loose, you can HEAR the rattle getting progressively worse, and the button overall feels really, really bad.
EDIT 3: Got the RMA from Razer. Recieved the replacement within a week. This mouse is perfect now, and I love it. Was it worth the hassle? Who knows