Hey there,
Can't speak of the Rival 3, but I have the Harpoon RGB wireless and I love it. Because of the internal battery it actually adds a nice bit of weight to it. It's sturdy, and good build quality. Typical charge lasts me about a week. That's with maybe 15-20 hours per week gaming, and another 5 hours for standard use. Charging takes about 3 hours. Connects via wireless dongle and also BT. The Bluetooth connection is not really meant for FPS gaming, but for some games is suitable. I use the wireless dongle, and in terms of connectivity, I've not had a single issue.
The Harpoon is well considered as a great budget Mouse:
Corsair HARPOON RGB Wireless Review - RTINGS.com