I agree with pretty much everything you said. I've had some bad experiences with Logitech in the past, but generally they are pretty good. I actually didn't like the Performance MX as it turns out (I like a smaller mouse), but I always suggest people check them out for comparison.
When I started looking at mice for my new iMac I thought I was only going to get a Bluetooth mouse (wanted wireless, didn't want a dongle; Bluetooth is the way to go); which basically means getting the Razer Orochi. However, I decided to go wired keyboard, wired mouse because there are better options (and I am a master cable-hider
).
Anyway, I looked at getting the Orochi and that is when I found out about Synapse. I looked into it, tested it out, and I have to say that I don't really care for it in practice, but I HATE it in principle, so I will never by anything from Razer again. You can find threads elsewhere on the net that go into more detail about the evils of Synapse, so I bother you folks with a rant on it here. The short of it though is that if you buy a new Razer product (or plan on being a Razer customer in the future) you need to get used to using Synapse as it (or something similar) with be required. This is why I've come to like Steelseries as they have excellent mice, but have not yet adopted (and hopefully never will adopt) anything like Synapse.