The go to ratchets on my cart in the shop are SO rotoheads. I have the 1/4", the 3/8" in the 1/4 body and the full size 3/8. I like them better then flex heads but there are times when a fixed ratchet would work better. I have a Genius version in my box on the service truck. There is no comparison. The ratchet mechanism is fine but the tool is heavy and unbalanced compared to the SO. I lose tools on my truck so I won't put an expensive SO ratchet on it.
Note, I bought these ratchets before getting into the used tool business (paid retail) and they are one of the few tools I would consider paying full price for again, especially the 1/4" version.
SK has a 3/8 rotohead that is quite good also. I have sold several of them.