When I posted earlier about the SWC as the "only" Hass to buy, I did forget about the motorised bodies which others did not skip on. After acquiring the (hugely disappointing) 503CW, I did go for the 553. For reasons likely related to overall added heft over non motorised 500s, it feels different, it sounds different, and handles different.
I'm on the bus carrying those who have hard time adjusting to how standard 500 box lands in the hand and operates, all of this is pretty much out the window with a motorised body. Add the still rather low price on these, competitive with any other MF brand, and so long as that extra height and weight is not a problem, you have a great controller of Hass lenses.
The best first tale of how badly a Hass was used is the condition of the back plate as it shows wear from switching film magazines. Motorised bodies were in their day just studio cameras and many went through significant repetitions. But even these days, there are many in near unused condition, as many were back ups, hardly saw any use.
To summarise my "Which Hass", SWC has its lens and does not require further investment in lenses, if that is all one needs. Once one goes with any other body, I want to point out the Flexbody, which to me after SWC and EL bodies is the one to remember about and "flexibility & fun" it adds to Hass kit.
All 500 standard bodies feel to me hollow, odd handling, and as such not what I thought I was getting into.