Swapping the Caps Lock key with the Ctrl key is a good workaround for a laptop keyboard, but on a full keyboard, there are many alternatives that are better. Here are the reasons why:
The above assumes that you do TOUCH TYPE.
If you do not touch type, then Ctrl at Caps Lock position isn't too bad.
Though, you really should learn touch typing.
I do touch-type, just not the standard way taught in school.
Try this. Put a towel on top of your hand over keyboard. Now, go thru your day coding. If you are fluent as usual, then, you do touch type.
Among tech geekers, it's widely recommended like a dogma, to swap Caps Lock and Ctrl keys. However, remapping Ctrl to Caps Lock violates some basic ergonomic principles.
In touch typing, modifiers comes in pairs, such as ⇧ Shift key. The accepted ergonomic way to press modifier combinations is using one hand to press the modifier key and the other to press the letter key. Using 2 hands avoids single-hand straining its muscle.
You can see how it is otherwise by disabling one of the ⇧ Shift key. With just one modifier, you are heavily handicapped. As a example, try this exercise:
TYPE THIS SENTENCE WITH ONLY THE LEFT SHIFT KEY AND WITHOUT USING CAPS LOCK.
Microsoft Sculpt Ergonomic Keyboard review
Buy a good keyboard that has big Alt ＆ Ctrl keys, and on both sides of the keyboard, and symmetrically placed with respect to your thumbs when hands in home position.
See also: Best Keyboard for Emacs.
You can use your palm to press the Control key, instead of poking it with your pinky. This can be comfortably done on most PC keyboards.
Another way is to curl in your fingers into a semi-fist, then sit your palm or pinky knuckle on the Ctrl key.
On a laptop, usually the Ctrl ＆ Alt are both tiny squares. It's impossible to use palm to press the Ctrl, and it's also not necessarily easy to use thumb to press the Alt. And often, there's only one set of these keys on the left side. The Caps Lock is the only big key and better alternative.
If you do not touch type, your hands do not fall into standard positions and are freely moving. The big Caps Lock key is a very easy and convenient target. Even if you do touch type, the key at the Caps Lock position is still best choice than the positions for Ctrl or Alt on a laptop keyboard.
Here are 3 methods of typing Ctrl:
Here's a very simple test anyone can do to see which method to type Ctrl is more efficient and less tiring.
Type the following. Whenever there's a Capital letter, hold down Caps Lock key as if it is ⇧ Shift.
YoU caN cAp The letTER tHAt yOu neEd to pReSs thE ModiFier liKE In thIs senTenCe.
Repeat this 3 times.
Now, take a break. When you are ready, do it again, but for each cap letter, press the Ctrl key at the opposite corner of your keyboard, and using palm or semi-fist.
Again, take a break. Now, for each cap letter, press the Alt key instead.
Repeat this test daily until you are very familiar and comfortable with all 3 methods . After a week, you should have a feel on which way is faster and or less tiring.
A [Ctrl] to the left of [A] is natural and what I've been using since the mid-1960s with absolutely NO problems or RSI whatsoever beginning with a TTY ASR33 and continuing with a Datapoint 3300, DEC VT100, Datamedia DT80 and others along the way to today.
Because you don't actually type that much. See: How Many Keystrokes Programers Type a Day?.
Mapping and using the [Caps Lock] as a [Ctrl] to the immediate left of [A] is no different than the ["] to the immediate right of [;] re: pinkies.
True, but most keyboards do not have Ctrl key at the Enter ↵ position. Even if you have control on both sides of pinky, the Alt keys for thumbs is still better, because:
A lot people have developed Repetitive Strain Injury from emacs. They are frequently posted to online forums. I regularly got email of scary stories of people who got RSI. Avoid it now before you got it.
See also: Bad Advices from Programers about Typing ＆ Keyboard (RSI)
See: Keyboard: Control vs Capslock Position.
Here's other view.