Which I fell for. Fool me once and all that...
Razer was never "definitively better". It's merely competitive with other top ones, that's all. Before G700, Logitech even had a mouse with two sensors and was the undisputed king for FPS quite some time.
Logitech is a truly innovative company. They actually care deeply about ergonomics. They also introduced the first mass market application of programmable magnets (in the MX Master mouse scroll wheel) - that's incredibly advanced materials science.
Currently I use their MX Keys Minis, MX Anywhere mice and trackballs. All are rock solid. Bolt receiver works great with Linux via Solaar allowing full suite of features.
Oh, Firmware Update Daemon supports Logitech hardware, too. If Logitech sends in new firmware, it pops up instantly to upgrade.
We've had them for years. The mini has lost the button that lets you select speed, but other than that they're still great. For better than the various Logitechs I had before.
The only real downside is the bright flashing led patterns. I've gotten used to them.
At least one person has put together a good overview of what they think is happening: https://www.youtube.com/watch?v=v5BhECVlKJA (details in video description)
The software allows for fine-tuned settings, button remapping, etc. It is awful software, to be sure, but it's not necessary to use the mouse.
[1] EloShapes find similar: https://www.eloshapes.com/mouse/find-similar
I'm currently using a wireless ProtoArc mouse. Good shape, can adjust DPI on the fly, hasn't broken even after a year. I think it was like 30 bucks maybe?
If you're really interested in FPS performance and not just the brand, choose for the ergonomics first, it's not possible to recommend anything without knowing your play style, hand size etc. The shape and weight you like, and complementary feet and mat with the exact static/dynamic friction you need. Then check if the internals are good enough (they likely are) and whether there are any firmware issues like extra jitter on flicks or unavoidable debounce lag, then look at the required software. There's a ton of mice with excellent performance that are configurable without ANY software.
This is unfortunately why I keep buying the Razer Deathadder Pro. It fits my hand perfectly and is super accurate. I hate their software, and the company, but the performance and ergonomics of the mouse are worth it to me.
https://www.eloshapes.com/mouse/compare?p=razer-deathadder-v...
https://www.rtings.com/mouse/tools/3d-model-shape-compare/3d...
If you never want to change the DPIs, lighting, or button assignments, & etc then you don't need the software... so if what the hardware does out of the box is fine for you, then you don't need to worry about how trash CORE v2 is.
CORE v1 is okay, but still notably worse than the Model O software. I don't know why they farmed out the development of CORE v2 to "the CEO's middle-school nephew who's 'good with computers'", but they did.
[0] ...they were originally called "Glorious PC Gaming Race" (in homage to the Reddit meme), but dropped that last bit from their company name a while back...
This is... frustrating. Multi-button HID devices are -arguably- easier to do than something that pretends to be both a mouse and a keyboard. I get that some games may not understand how to deal with mice that have more than four or five mouse buttons, it'd be quite nice if I had the option to set things up so that I can use them as buttons in games that know how to handle them.