I completely agree. While it was obvious that Halbrand was Sauron, part of me wanted Sauron to be literally anyone else.
Sauron is a Maiar, he was an angelic and divine being, I would expect a mortal guise that befits that status. Halbrand is a literal hobo with filthy clothes.
It's like the dragons in WoW. Notice how the Aspects (Alexstrasza, Ysera, Nozdormu, Deathwing...) all took badass, iconic, and mighty humanoid forms. Now imagine Deathwing disguising himself as a hobo, that's Sauron as Halbrand. It doesn't really fit the character, who would be too proud and self-absorbed to take on such a filthy form.