A few of the minor downsides to the M1 over a straight target turret.
1. Less area on the turret for engraving.
2. Larger size makes it more prone to accidental adjustment while traveling in pack or scabbard.
3. Larger size makes optic slightly more bulky and optic takes a few more bangs
4. The Shroud tends to hold debris.
5. No way to cover the turret in situations where you want a cover.
Nothing very earth shattering but I can�t find any advantage the M1 has over the Target Turret
Of course #1 only counts if you use engraved turrets, and #2-3 are subjective because the M1 is wider, but the TT is taller. Numbers 4 and 5 are definitely valid, although I've not had either one cause a problem for me so far.
The advantages to the M1, IMO, are that it's slightly shorter, it is easier to spin with numb hands, and it's quicker and easier to read than the TT.
You're right, none of the differences are earth shattering. It's mostly just a matter of preference.
