Have you ever wondered which הגדה would provide the most authentic text along with clear דקדוק guidance? I used to. But a newly re-published הגדה solves it all - שירת הלויים - מבית בריסק, authored by Rav Aryeh Leib Lopiansky. The text of the הגדה has been combed through and edited by none other than Rav Nissan Sharoni, author of the renowned אם למקרא ולמסורת. Accents and שוא נע's are indicated and you will find corrections to some of the more common textual mishaps found in most הגדות, such as דְזַבִּין אבא, as we have discussed.
This is a rather large volume. The הגדה portion is at the front with commentary from various Brisker גדולים followed by a larger section filled with longer shtiklach on various ענינים related to the סדר. I just picked up my copy locally.
As a visual aid, this is what you should be looking for: