Many think that the Ḥafṣ version written by ʿUṯmān Ṭaha and distributed by the Saʿūdīs
is the standard, because more such copies exist than others.
This is a misconception:
Turks who get one during the
haǧǧ do not open it, give it away or put in a vitrine,
West Africans get a Warš copy written by ʿUṯmān Ṭaha,
Indians and most Asians (even Iranians) get a slightly improved copy of the Indo-Pakistani standard,
known as the Taj Company Ltd. Standard
((the Saʿūdīs took the 611 page
muṣḥaf ‒ earlier reprinted e.g. in Kašgār ‒ but paid
attention that the standing
fatḥa never precedes alif for /ʾā/ [not /āʾ/!]))
Maybe that the Saʿūdī copy according to the Egyptian government print of 1952 is the most printed,
it is definitely not the most bought.
Muslims buy many more copies of the Indo-Pak version.
For a simple reason: there are five times as many Muslims hailing from the Indian subcontinent, from Indonesia and parts of Central Asia under Indian influence than Muslims from Egypt and the Arab Middle East.
But isn't the Egyptian text better?
First it is the Maghrebian
rasm, with Maghrebian
tanwīn signs,
with Maghrebian
sukūn on (some) unpronounced letters and Indian
ǧazm on unvowelled letters,
with Egyptian
ǧuz-/ḥizb-divisions, with a streamlined Indian system of pause signs.
Second,
and more important:
The new "Arab" and the older "Indian" standard are of equal quality.
The Turkish is not as good because it notes /ā/ and /ī/ but not /ū/ when there is no
ḥarf al-madd in the
rasm and
it ignores assimilation.
The Libyan
Muṣḥaf ad-Dānī (originaly
Muṣḥaf al-Jamāhiriyya) is better because its
rasm follows ONE authority and not a (undeclared!!!!) mix.
To make a good
muṣḥaf, isn't easy because
the text, the sense, the words and the grammatical structure have to be right,
the sound, the pronunciation,
at-taǧwīd have to be right
but pronunciation changes slightly depending on where one pauses,
so the little signs around the
rasm have to take different pauses into account,
and they must indicate the grammatical structure even at places
where the case endings are never pronounced.
Turkish and Iranian standards are not as good as Arab and Indian,
because they do ignore assimilation.
But the Egyptian/Saʿūdī standard is better than the Indian, is it not?
It is not.
Let's look at
tanwīn:
Tanwīn is a short vowel /a,i,u/ plus a unvowelled nūn
(fatḥa/kasra/ḍamma + nūn sākin)
So the pronunciation rule for
tanwīn is the rule for
nūn sākin:
("dan" is Malay for "and", "contoh" for "example")

Depending on the following letter EIGHT things happen to unvowelled nūn:
1.) fully pronounced,
iẓhār إظهار before the letter h, ḥ, ḫ, ʾ, ʿ, ġ
8.) pronounced as mīm
iqlāb يقلاب
4.)
idġām kāmil bi-la-ġunna before rāʾ and lām:
the nūn is completely assimilated to the following letter, resulting in /rr/ resp. /ll/
3.)
idġām kāmil bi-ġunna complete assimilation with nasalization before
nūn and
mīm
2.)
idġām nāqiṣ bi-ġunna incomplete assimilation with nasalization before the glides
yāʾ and
wau
5.)
iḫfāʾ suġra small reduction, not full articulated before k, q
6.)
iḫfāʾ wusṭa medium reduction, reduced articulated before z, ḍ, ẓ, ḏ, ṯ, ṣ, s, š, ǧ, f
7.)
iḫfāʾ kubra big reduction, weakly articulated before d, t, ṭ
In India, Indonesia, Turkey, Iran there is only one
tanwīn sign for each of the three short vowels,
which is fine: the next letter makes clear, how the
nūn has to be pronounced.
In Bombay (and other places in India and earlier in Indonesia) a small
nūn is added after the
tanwīn to stress
iẓhār.
In Arabia there are not EIGHT different
tanwīn signs, but three,
which does not really help: One still has to look to the next letter.
AND: For
iqlāb there is no
tanwīn sign encoded in the Unicode,
which leads to utter confusion:
In the digital data stream of the qurʾān
tanwīn iqlāb is not encoded as
tanwīn. but as simple vowel sign!
So which is better?
Which should serve as Standard?
There are many sites in the web devoted to Islamic manuscripts,
but only one devoted to both manuscripts and prints, Ali Akbar's Indonesian/Malay archipelago
blog.
He gave me images from Indonesian "Bombay prints", always page 3, verses 5,6 of al-baqara:

The third spot I highlighted is an
iqlāb mīm, common in all maṣāḥif, the first two
iẓhār nūn, very rare ‒ why?