Here's my $.02 on it --
Both the ambi slimline switch and the DG switch can be operated with either hand.
The TG switch is activated by pressing upward with the offhand index finger.
I am doing more ambidextrous shooting so I appreciate the options presented by the DG and slimline switches.
Between the slimline and the DG switch the differences are not great. I find it slightly easier/more intuitive to activate the DG switch due to the straight-back press that is part of my normal firing grip. The slimline switch requires my middle finger to exert some pressure to the side of the grip which doesn't feel as natural, but that may be due to the way my XXL hands wrap around the grip. The slimline switch looks like it would stay in place better, but the way the DG switch wedges in using the top finger groove is pretty secure as well.
Thinking of white-light ND's, I don't see much difference between the slimline and DG switches. It's easy to ND either of them. I had expected the slimline switch to be more prone to ND's but for me it is slightly more difficult to ND the slimline switch because the activation is slightly different from my normal grip.
The slimline switch gives the grip a slightly odd feeling due to the "bump" of the switch encircling the whole grip, whereas the DG switch just has one little bump where there are already bumps (the finger grooves).
On the 1911 I prefer the TG switch to using the rocker, but I would rather have a DG or slimline switch for it. AFAIK the TG is the only switch currently available for the 1911.
I much prefer the beam of the x200B to the x200A.