There is a machlokes in the gemara if one is yotzei if he didn't enunciate all the words of shma properly [קרא ולא דקדק באותיותיה]. The Rambam rules that ideally one should be מדקדק באותיותיה but if he didn't he is still yotzei.
The Rambam writes [hilchos krias shma 1/4] that one says the pasuk of shma and then says ברוך שם כבוד מלכותו quietly and then says the rest of shma " כדרכו" - in its way. What is the Rambam telling us with the word כדרכו?? He would have been perfectly well understood had he just said that after ברוך שם you read the rest of shma!
The Brisker Rov wondered if ברוך שם which is not from the chumash is included in the exhortation to read with דקדוק אותיות
MAYBE the Rambam is telling us that it is not necessary. Only the REST of shma must be read כדרכו i.e. בדקדוק אותיות but not ברוך שם.
The Tur says that psukei d'zimra and shmona esrei must be read בדקדוק אותיות. The Beis Yosef cites the Radak who says that whenever reading Tanach it should be done with דקדוק אותיות.
It would seem to emerge that according to the Tur even ברוך שם must be read properly just as the rest of davening must. However according to the Radak the din of דקדוק אותיות applies specifically to Tanach and thus ברוך שם [which is not a pasuk] would not be included in the obligation to read בדקדוק אותיות.
גבורת יצחק עמוד רב
What do you think??