Ok, I received the left handed evoluent vertical mouse 2 (VM2-LSB) and I've been using it for a few days now.
Overall impression is pretty good, but you need to get used to it. It detects fine under Linux and seems to be manufactured by somebody else, hmm ok then.
input: Kingsis Peripherals Evoluent VerticalMouse 2 as /class/input/input10
input: USB HID v1.10 Mouse [Kingsis Peripherals Evoluent VerticalMouse 2 ] on usb-0000:00:1d.7-6.1
usb 2-6.1: New USB device found, idVendor=2222, idProduct=3061
usb 2-6.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
usb 2-6.1: Product: Evoluent VerticalMouse 2
usb 2-6.1: Manufacturer: Kingsis Peripherals
Now I must admit, I did want a wireless left handed version, but alas they claim it's not going to be made. Hopefully they will change their mind at some point. There were a couple of other reasons why I would like to try a rev 2 left handed version. Firstly, what to do with your pinky! I am finding that I tend to have to have it sticking out and resting on the table when I hold the mouse, since trying to put all your fingers on the mouse doesn't work that well for me, it's just too crowded when trying to use all the buttons. I tend to place my 3 inside fingers on each of the 3 buttons.
Now, the rev 2 seems to have been been modified with a lip/flange on the base for your pinky finger, I'd like to see if that helps or hinders. The other small niggle is the scroll wheel. It's good enough I guess, but the rev 2 also has a bumpy style scroll wheel apparently which I now declare I prefer after having used the smooth one on this version. Personal preference I guess. I've also defaulted to using my index finger for the scroll wheel, I think it's easier.
If there is one thing I don't like about it, it's the smooth glossy almost cheapish looking light gray plastic that is used for the buttons and most of the front. The finish just makes it look and feel a bit cheap, like all the $5 mice out there - a slightly textured finish or really anything else would be nicer. No complaints really about the other black plastic used, perfect for that part of the mouse.
While it has only been a few days, I have noticed a small reduction in my ongoing hand strain, though it's too early to tell how much better it will be, but I am happy with any level of improvement. The Evoluent mouse is quite natural to hold, it's optical sensor is very accurate, the default speed is sensible and I suspect becoming more comfortable with it as time goes on. If I end up seeing more improvement, I will also splash out on a right hand version and switch between them to minimise any RSI.
Have a great day lefties... oh ok... righties too...