We've lauded Logitech's G5, G6 and G7 series. Here, the G9x comes with all the features from previous versions.
Particularly worth of note is the standard selection of weights (4x4g and 4x7g) which can be added to the mouse via a slide out drawer. Accessing it is slightly tricky - you first have to remove the clip-on grip, before pressing the pop-out tray.
There are two interchangeable grips - one is a slippery silver with chubby buttons, the other is a roughened charcoal shade with less pronounced buttons. The interchangeable grip doesn't feel entirely satisfactory.
The weight placement is good for smooth movement. Even so, we're not entirely convinced by it: for starters, the alternate grips are gimmicky, and don't add terribly much to the whole experience.
It would be remarkably easy to accidentally break one, too. It's a nice mouse, but the construction feels less sturdy than previous versions - we managed to get the weight cartridge stuck in the body of the mouse at least once - and it's not nice enough to outweigh our love for previous models.