I mean, you play FPS mostly right. So getting the NAGA is abit of an overkill since you won't be using half of the button is has on the mouse and you'd just be paying more for features you won't be using. In shooters you only need, well essentially 2 buttons and you're good to go. Having an additional 2 side buttons is great when it comes to web browsing and stuff. But throwing money and getting a NAGA is just paying for features that you won't be using since the NAGA is aimed at MMO players with it's 12 programmable side buttons.
The Razer Taipan and diamondback are a pretty low profile gaming mice. And personally, I find them giving my hands an ache after gaming on them. Since I prefer a higher arc mice that's why I chose a Razer DeathAdder for my own needs.
But all these are my own honest opinion. Getting a NAGA when you're a FPS shooter player means that alot of the function and features on the mouse are going to be under-utilize making it not cost-effective.
And personally, the taipan and diamondback are too low in profile making my hands ache which YOU may not find that an issue since all of us are made differently.
😀