A look at kedushah in davening
Kedushah is one of the most important, and prominent, parts of davening. So much so, that a typical regular Shul goer will say it three times each standard weekday morning with his minyan: once in ברכות קריאת שמע, once in חזרת הש”ץ, and once before aleinu (קדושה דסידרא).
It should be noted, however, that the three קדושה recitations are not totally identical and interchangeable.
The first one, in the ברכת יוצר אור, appears in a context of a more lengthy and more detailed description of the heavenly sphere, and how the angels there praise הקב”ה.
The second one, in the shliach tzibbur’s חזרת הש”ץ, is an attempt by us humans in actual angelic imitation, sanctifying Hashem’s name in this world, as it is done in the heavens above (as per the introductory words to it). To that end, not only do people say it standing, in the manner of מלאכים above (as opposed to the other two, which are typically said seated), but they also customarily recite it with legs and feet together as well, imitating the posture of the angels, as well as rocking up and down on their toes at certain points for the same reason.
The third one, is done by reading the פסוקים (verses) as given in תנ”ך, accompanied by their Aramaic targum (translation), surrounded by a collection of other verses from various places.
The special status of the kedushah of the שמונה עשרה historically
We have shown so far that the קדושה דעמידה (standing kedushah during the repetition of שמונה עשרה), is special, and different than the other two recitations, being an exercise in actual angelic imitation.
Since it is already treated in such a special manner, it would be quite appropriate to elevate and strengthen it even more, if possible, within the bounds of our tradition, by extending the angelic imitation even further. In fact, if we look into the matter thoroughly, we will learn that in ancient days (and to this day in part or full in some communities), the קדושה דעמידה was recited differently than the most commonly practiced way of the present.
How exactly was it done, you may ask? The answer is, that as opposed to the congregation saying the introductory segment of נקדש את שמך בעולם, וכו, in addition to the חזן leading the prayers, that segment (as well as other segments not being actual pesukim recited up above) was reserved for, and recited solely by, the שליח ציבור, with the congregation listening to it in absolute silence, in a hallowed hush that came over the assemblage. That extended hallowed hush, a thunderous speaking silence, brought an additional aura of heavenly holiness to the proceedings, cultivating the proper mood for the actual kedushah to shortly follow. Those that have merited to experience this very special and historic manner of saying kedushoh know what I mean.
In ancient times, that was the way of saying this kedushoh. Both in אשכנז and ספרד. In recent centuries, however, many people and congregations departed from it (often in a mistaken belief that they were following an alternate way of the Arizal), to the point where today, it is a practice followed only by a minority. But this venerable, meaningful, and powerful מנהג ותיקין is still practiced, known, and cherished, by connoisseurs of tefillah and old minhogim, and stands waiting, with ancient, venerable dignity for restoration to the position of common practice that it had in the past (as we discussed previously, based on a psak of Rav Moshe Feinstein zt”l).
Some reasons for conducting קדושה דעמידה the ancient way:
1) The angels don’t give such introductions before saying this kedushah on high. So why should we, when claiming to imitate their practice, do so? (ר’ דוד אבודרהם , renowned Sepharadic ראשון).
2) Practical benefits of increased focus it brings to קדושה, with more power, and ancient aura added. For those who have never experienced it, try it sometime. It grows on you too.
To focus in on this a bit more, and elaborate on how it works, I am adding some analysis, as it seems from here, לעניות דעתי, based on a typical נוסח אשכנז weekday קדושה.
a) The introduction, נקדש, וכו, is, by far, the longest segment of the kedushah, at a length of 18 words. The other parts that are not pesukim, namely לעומתם ברוך יאמרו, and ובדברי קדשך כתוב לאמר are an additional 7 words. That computes to a total of 25 words for what we can call the instructional and explanatory segments.
b) The essence of the kedushah, on the other hand, the actual פסוקים, total just 21 words.
Those who make the tzibbur say both parts a and b, are having them recite forty six words. On the other hand, those who limit them to the pesukim only, give them just twenty one words to say. So the second way then, reduces by more than 50% the required recitation, enabling a better focus on the essence that remains. It is known that requiring people to say more words, can lead to increased speed, and a dimunition of kavannah. As stated in the first siman of שלחן ערוך אורח חיים, quality trumps quantity, טוב מעט בכוונה מהרבות בלא כוונה.
3) Say the קדושה of the מלאכים the way the ראשונים כמלאכים said it. Experience the kedushah of the רא”ש, בעל הטורים, מהר”ם מרוטנברג, מהרי”ל, ריטב”א, רשב”א, רבינו יונה, וכו’, וכו
For further study and contemplation
For those who wish to learn more about this, the matter is discussed at greater length in the great שרשי מנהג אשכנז חלק א (an updated and expanded version of the long out of print volume awaits sponsorship for publication at this time), as well as in the Shorshei Minhag Ashkenaz English language synopsis volume.
כידוע למבינים, a slight bit of tweaking, of adjustment, can go a very long way, and bring a huge payoff in the form of greatly enhanced results. That goes for things like a car tune up, a Chanukah menorah, a cooking light, as well as with עבודה שבלב, and our קדושה recitation.
This beautiful minhog has been preserved through the centuries (in greater or lesser measure) by followers of מנהג אשכנז in German lands, as well as some others, for example people who follow מנהג הגר”א מווילנא. Hopefully those in this new seeking generation who are not yet familiar with it, will grant it the consideration and respect it so rightfully deserves.
יה”ר שבזכות החזרת עטרה ליושנה נזכה במהרה להחזרת השכינה בשלמות למקומה
א גוטען חודש
TREASURES OF ASHKENAZ 
מה אתה חושב? וואס זאגט איהר - What do you think?