Chandavkl's recent post about his baked cha sho bao ecstasy at Blue Sky on Powell nagged at me until I went there to check it out myself. I wasn't exactly stunned (maybe mine wasn't as fresh as his), so I decided to do a side-by-side comparison with my (and Dave's former) go-to, You's on Broadway.
The bottom line on the comparison was that there really wasn't a lot to distinguish the two other than size and price. As can be seen in the pics below, the Blue Sky version (on the left in both pictures) is considerably smaller. This can be seen better in the second picture; it had become a bit deflated while carrying it around in my bag for a while. BS also had a slightly lower meat-to-bun ratio. I didn't have a scale around, but it appeared that the You's bun was at least 50 percent heavier; at 85 cents per bao, it was also almost 50 percent more expensive than Blue Sky's (60 centesw).
Both baos had a very similar filling, small thin slices of bbq pork is a sweetish, corn-starchy sauce (pretty much a standard recipe). As Chandavkl noted, the Blue Sky version had a fluffier, yeastier wrapper, while the You's version slightly more cake-y with a little more "crumb." The BS version also had a shinier glaze.
I guess it comes down to where you happen to be, or how you want to divide up the booty, since you can get three of one for about the same price as two of the other.
I would choose Cafe Bakery's (Noriega) or Gourmet Dim Sum's (Clement) over either, except these tow happen to be in my neighborhood.
Blue Sky is at 1504 Powell, You's at 675 Broadway.