just got my 28 carbs from TYGA. those guys are the dog's bollocks! accidently sent me 21 carbs so they sent the 28s and let me keep the 21s. .....good stuff!
the reason I went with the 28s is because they are updated versions and are a much simpler design. they're physically smaller also.. i just figured i can replace my worn 21 carbs with these 28 pieces.
plus...its always good for more poser points.