I don't own an ergonomic keyboard, but considering getting one.
Ever since I read the following comment (at http://mindprod.com/bgloss/dsk.html#ARENSITO)...

"I was puzzled over the Arensito placement of the infrequently used g and b in such prime real estate and the demotion of c and h to the awkward bottom row. Hallingstad explained that he found it easier to bend the finger than to move it sideways, especially on Kinesis and Maltron keyboards."

..I have wondered, is that a common consensus among ergonomic keyboard users?
In other words, do most people agree with Hallingstad estimations of strain for each finger using an ergonomic keyboard?

(figures for right hand)

Obviously these different parameters, when compared to a standard, flat keyboard, would (do) produce different optimized layouts, so your choice of layout boils down to how much time you have to spend using each different type of keyboard and how important you feel it is to be using a layout with at least some chance of becoming widely adopted.

Considering finger-operated keys alone, the differences are probably just minor tradeoffs. The big sticking point however, that makes this decision harder, does seem to be all those incredibly useful thumb keys, which give all kinds of possibilities for improvement (like the Maltron layout) which are more or less unachievable on a standard, flat keyboard. Choosing to use layouts which make fundamental/ingenious use of them like that, is unfortunately going to put you at odds with moving seamlessly back and forth between keyboard types.

What are people's experiences using the Maltron Layout?
Is the 'E' on the thumb weird to get used to at first, or just seems natural?
and does it turn out to be a significant enhancement?

Thanks, Jon

I've been using the typing method recommended for the Arensito on a normal keyboard (but I'm not using Arensito) where the whole keyboard is shifted up one row and the thumbs get the bottom. I have shift and backspace under my left thumb, and it makes my thumb sore. Shift plus backspace is still less usage than E. So I'm sure E would be even worse.

My thumbs are surprisingly weak.

The muscles in both joints in my left thumb hurt a little when I used them. I presume it's from typing on that keyboard, because the pain went away when I started using QWERTY more.

I don't think that would help. See previous question.

The way I'm doing it, the spacebar is used for the AltGr layout.

I'm using the MTGAP's Layout (MTGAP is my other internet alias). It's hard to read on my website because I suck at HTML. Copied from my website:

The designer of Arensito had 2 really great ideas. The first was to have a whole different layout for special characters, accessed with AltGr. I'll get to that later. The second was to a way of using thumb pads on a standard keyboard. All the keys are moved up 1 row, and the thumbs go on the bottom row.
UNSHIFTED SHIFTED
q , f h d k j c u l . - = BKSPC || Q ( F H D K J C U L ) _ +
TAB o a n t g m s e r i / [ ] || TAB O A N T G M S E R I ?
CAP q x b p z y w ' v ; ! || CAP Q X B P Z Y W " V : &
shift _ 5 3 2 _ 1 4 _ _ _ shift     (those underscores mean no key)
AltGr(used to be space)
I put Q in the tilde position because of the Mac shortcuts CMD-TAB and CMD-Q.
1: space
2: backspace
3: shift
4: enter
5: a dead key that causes the next key pressed to be its QWERTY position. This is mainly for keyboard shortcuts: hit this key, then hit CTRL-C where C is in its QWERTY position.
About that special characters layout. You press AltGr to access this layout.
9 7 5 3 % $ 2 4 6 8
/ = * 1 \ _ 0 : ; #
< > ^ + | @ [ ] { }
This layout puts the most common special characters on the home keys. It's also easy to remember: I spent no time trying to memorize it, but I have no problem remembering it. Odd numbers are all on the left, and evens are on the right. All the paired symbols (like brackets) are on the bottom. All the mathematical symbols are on the left. \ and |, which are on the same key in QWERTY, are next to each other. As a little bonus, % is in its QWERTY position.

I think this layout feels really good. The hand alternation is pretty bad, but the keys are all in positions that I like and it rolls very well, and same finger is low. The most frequent same finger thing is "my", and that's easy to hit by rolling the index finger downward.

My left thumb hovers over QWERTY-C, which is shift. My right thumb hovers over QWERTY-N, which is space. That's where my fingers naturally rest, and I decided what to put there based on where my fingers rested. I've found that shift is more common than backspace.

I keep it on ASDF. Well technically it's QWER, but whatever. I keep it there because I use a laptop, and the keyboard is attached to the screen. What that means is, if I move my hands over, I'm off-center with the screen and I have to bend my neck weirdly.

So there's a bunch of keys in the middle? Interesting idea. I wouldn't want to do that, but I guess you could. That would mean there's no key below the right pinky. It would put more work on the index fingers and less on the pinkies, especially the right one. That would make U, J, and M very hard to reach.