It's an interesting question for sure! I think that the extra time required for punctuation may be largely offset by the better typing flow of real text. It should matter what you're used to as well, so typing in the eventually very familiar Amphetype window may get you in the flow better than in some "foreign" window.
I have the same impression as you. But the book I'm typing in Amphetype now (Behrens' Greek and Roman Mythology) has some passages with a ton of capitals, punctuation and weird references looking like this {193} one; those do slow me down by at least 10–20 WPM. Interestingly, I don't care about using CapsLock but just hold down a Shift key while typing ALL-CAPS TITLES GALORE. (Whoa, the hyphen does trip me up dangit.)
The masterful Sean Wrona specifically prides himself on being able to type extremely difficult text in flow. So I think one can get used to that. Once you're in good flow, a shifted symbol character is nothing more than two key presses with a slightly longer jump. But getting there takes practice ... and the ability to stay calm.
Note that Wrona also uses sticky Shift to avoid having to hold down the Shift key. At his speeds, it gets too tricky to time a hold-down modifier so that you get One True Character Shift and not DOuble CApitalization UGliness. I believe he's right, but I haven't gotten quite used to it yet. I've implemented Sticky Shift in my TMK files, but in OSes you still have to activate it in system menus.
Last edited by DreymaR (06-Oct-2017 13:09:15)