Smooth scrolling, nice looking trackball. After communicating with customer service, I received a replacement very fast. Great customer service. The trackball works very smooth, very precise, using it for graphical works, as well later on using it for gaming, satisfied with both use cases. Love it's very light and wireless, only one click to switch between work system and gaming. The trackball holds charge pretty well even when the RGB lighting is always kept on. The trackball is very similar with the classical Microsoft Explorer, the noticeable difference, Microsoft used 46mm ball, Nulea is stays with 44mm, but, it feels comfortable, and I haven't noticed any issue with the ball being slightly smaller, on the other hand new bearing system is better than the stainless steel being used in Microsoft version.

I use this mouse every day at work, it is very precise and has a good battery life. I charge it once every 2 weeks.

It's really hard to find a good trackball mouse these days but I picked this one based on it's features and price point. It can support up to three devices but the active device selector buttons are on the bottom of the mouse instead of the topside which is really annoying if you need to easily switch between paired devices on the fly. I like it that the mouse is rechargeable, but I have to recharge it more often than my other rechargeable mice so perhaps the light ring surrounding the trackball drains the battery faster than mice without lights. The trackball falls out easily but it pops right back in. Performance wise the mouse is responsive but the button clicks are easily heard in a quiet space which may be disturbing for some people. Overall I've been happy with this mouse even with it's minor design annoyances.

If you like the Microsoft Trackball version this one is the replacement for it. I bought another version first but no matter what you do to clean it it starts sticking on the ball and becomes unusable after a few minutes.The only downside for this one is the buttons are not programable but basic functions are there.

This is my second tracking ball mouse. Only difference is the other one does not have lights. The battery drains quicker and the tracking ball is a bit stiff. I have cleaned it and it still if stiff.