I quickly modified a couple of pictures to help explain the handle points a little better: the blue lines indicate contact between the handle and hand during a normal grip, also being points of exaggerated pressure during forceful cuts. The Red-line indicates a point of reduced or absent contact between handle & hand.
A straight spine focuses pressure on the muscles groups south of the 'pinkie' and between the thumb and forefinger, and forces the hand flatter against the spine. The RMD's curved spine allows this pressure to be more evenly distributed across the hand without forcing the hand to flatten-out as force is increased.
Now, the fact that the GSO-5.1 handle is laterally thicker in the palm is certainly beneficial, a trait that the RMD handle would benefit from (or rather the user would benefit), but the hand is also contoured vertically, and in this case the vertical contours are key.
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Minimal curve on the spine creates LESS comfort "throughout a range of different grips"... In every grip I have tried, the curved spine of the RMD fits the hand better. The human hand forms a "pocket" in the palm (that the lateral swell acts to fill), but it also curves around the thenar muscles. ... the RMD ... curved spines to accommodate this curvature in the hand. As a result, ... distribute force along the hand more evenly than a straight spine, as illustrated above. In reverse grip, the curve along the belly (more common in various knives) approximates this as well.
The straight spine focuses pressure onto specific areas of the hand, forcing the hand to change shape to accommodate handle rather than the other way around. As a result, the straight spine is always less comfortable for any human hand.
Please note, I am only criticizing the spine of the handle. Other important factors include the "heel-drop" which allows increased leverage from the lower portion of the hand to take pressure off the higher portion, and also the lateral swell the allows the fingers to grip tightly without straining. However, with thicker handles it is important to consider how this impacts control of blade direction, requiring a wider handle to compensate. A rounder handle, like the Bravo 1 and Catt225Q, is easily twisted against the user's grip, and is thus harder to control and is even dangerous in adverse conditions, particularly if the handle is slick. Superior control is achieved by maintaining a greater width (height) than thickness, which the RMD and GSO-5.1 do well, which the GSO-10 excels at.
These features are not "to each his/her own", the human hand is configured and functions with great consistency in nearly every human being - the size and proportions of various parts aren't identical, but the parts are in the same places. While your hand may be larger and require a larger (both thickness and width) handle in order to be comfortable, the points about shape remain the same, because the shape of the hand is so consistent form human to human. If not, you may have a hand that is worth medical research!
Neither will lose value, it may even go UP. If you order an RMD from the shop, be sure to specify an edge angle as they tend to send their knives rather obtuse for higher impact durability at the expense of decent cutting performance. It takes a while to bring the edge angle down to where it can compete with the GSO-5.1, but you could ask them to grind it how you want it at the factory.
