Pretty much all the Holley carbs have gaskets below fuel level and it is an imminently successful line of cabs. Many carbs have side hung floats, including all of the 1850 4 BBL Holley carbs which have been great for about 50 years now! And many carbs suffer from bad accel pump diaphragms. The Carter BBS has issues with worn out shaft bushings, so add that to you list of carb deficiencies. None of these items are 'inherently' bad as they are common to many carbs.
Geesh, what is with the obsessing over 1920's? I read that you had fits with your Holley 1920 (s); many (most?) others have not. An opinion and experience is fine, but it is just that: an opinion and an experience. So do the new guys a favor and be upfront that it is just your personal viewpoint. I had ZERO issues with the rebuild of my 1962 vintage Holley 1920 but I don't go around praising them as the end all and be all of carbs just because it worked out fine one time.