At work I use a Maltron keyboard with Maltron layout. I like this keyboard quite a bit, but wish I had gotten cherry browns instead of blacks. Otherwise I love this keyboard.
I also quite like my typematrix 2020(dvorak), the low force keys are a delight, but I prefer a split keyboard and also 3d bowl shape.
At home I have a yogitype(dvorak). I am still trying to figure out how I feel about it. I like the design, and the matrix layout for the left hand but the staggered keys on the right hand bum me out. Also the keys feel much stiffer than the TM2020, though they are still fairly easy to press. Also, its not really ideal for programmers because keys like home and end require holding down a function key. I WANT to like this keyboard but I am going to end up replacing it with a Maltron with browns. I think the yogitype could be ideal for many people. It is well made, and really easy to learn to use because of the leds. In addition, the wrist position is excellent. However, my RSI is mostly in the fingers, and the stiff keys and lack of contour are ultimately deal breakers for me.
There is only one input device I would ever unequivocally recommend, and it is the datahand. The datahand is the best input device ever made from an ergonomic standpoint. The only problems with it were high cost and poor build quality, but form a usage standpoint it was ideal. The datahand is the only input solution I have ever seen which actually eliminates repetitive motion. Let me put it this way, if someone remade the datahand and backed it with lifetime warranty, I would be willing to pay a completely unreasonable amount for it(ie 20k+). I paid 2k for one, and I would be using it to this day if it had not been so flaky. I am a programmer so I rely on my hands too much to have an ergonomic solution I cannot rely on.
I have tried the kinesis advantage but prefer Maltron because the 3D contours felt deeper to me on the Maltron. I did not actually measure this.
edit: one thing also I tried was two one handed Maltron keyboards with brown switches. I did not really think this through as these keyboards were not designed to be used together. They were simply too wide to too used effectively at once. I will say these keyboards are excellent in their own right, and extremely comfortable to type on one handed.
I am going to order a custom bespoke keyboard from Maltron and I will make a new post when it arrives.
Also, in case you are wondering, I prefer Maltron to Dvorak layout. Maltron is really nice, and well worth the effort of learning a new layout. I have never tried Colemak.