I used to use a Logitech mx500. It made this high pitch noise, like everyone elses. In addition it was very heavy. I once opened it up, and removed a metal weight that was screwed in to the chassis. That took it from maybe 126g to 113g but can't remember for sure. Also I removed the small bent metal wire piece that makes the mouse wheel clicky, in effect making the mouse wheel free spinning.
These modifications helped a bit, but eventually I bought a Razer Lachesis and an Ulti-Mat Original teflon-covered metal mouse pad with rubber bottom. The Lachesis had weird bugs at first: The cursor would react weirdly to moves, stutter, and occasionally it totally lost it's vertical or horizontal axis, only making the cursor move in one axis. As I searched the web, both of these were known problems, and there was a firmware update that I installed to my mouse, and it did indeed fix both problems. However I find it very odd to need to do any firmware updates to a mouse. In my book, mice should just work.
There is still one bug remaining: Occasionally on reboot or power up, the mouse does not initialize, and the OS does not find it. Often when this happens, the mouse led starts flashing very rapidly. Only way to fix it is to replug the usb connector of the mouse to the PC, or power cycle. This last bug only happens quite rarely, but it does happen on both linux and windows, so it must be a hardware problem.
The led can indeed be disabled for good. Factory preset is blinking the led slowly. That's total crap I tell you. Who on earth wants a blinking led in a mouse? Even the most die hard bling-bling fan would probably get annoyed when he/she is trying to watch a movie with lights dimmed when your freaking mouse is blinking, let alone me who does not like such visual noise in the first place.
For disabling the led you need to have some windows machine, install lachesis control panel, connect the mouse, and set the led off. Then the led will stay off forever, in any computer you connect the mouse to. This is what I did, since I do not know of a way to turn it off from linux. There are actually 2 leds, the other lights the palm of your hand, and the other lights the scrollwheel. I let the scrollwheel light stay constant, and it serves as my power indicator, if I need to know if my computer is on.
The Lachesis is indeed silent, I can't hear a thing even if I put it against my ear and close my other ear with a finger. The surface is nice smooth rubber, instead of just plastic. There are no seams between the palm support and the buttons, which is nice. The chassis just bends enough to let you click the buttons. The side buttons however are way far too heavy to press, so I never use them. They have been made heavy on purpose so you wouldn't press them accidentally, but they are too hard to press even on purpose imo.
The Lachesis is also light, under 100g. There are no extra weights anywhere. This is very good, since together with low friction teflon pads, it needs very little force to move around, stressing ones hand less, so less chances of RSI.