Playstation 2 emulation is pretty good from what I've tried. 2D games seem to emulate better for me when using software rendering mode. The graphics plug-in also supports DirectX 11, but I don't know how much or in what way it helps. Probably a more efficient API.
I don't want to look like I've just ignored your suggestions, but I went with the Hori Ex2 Turbo in my original post because of analogue stick placement (prefer it above d-pad, since this gamepad will be for 3D-focused games). I mentioned Playstation 2 emulation, but it was not really a huge focus. I had no idea that the Xbox 360 controller had L3 and R3 buttons, which is great for Playstation 2 emulation, but I absolutely hate when games actually use them. No pressure sensitive buttons, though. I wonder how many Playstation 2 and Playstation 3 games actually use them. That's another feature I dislike since it makes the buttons feel mushy and like I'm never pressing hard enough. Also, fuck games that expect you to press it into just the right range to execute certain moves. Makes it even worse than L3/R3.
By the way, are Xbox 360 controllers supposed to have a limited analogue stick range? When looking at it through control panel, I see that the range is at max, but physically I have not pushed the stick all the way in that direction. It's a small amount, but definitely noticeable.