I think that is a marketing question rather than a technology question. I have both types of machines, just a few gen4s left. I have had gen3 and earlier machines as well. If you do basic maintenance you can make either last almost forever. For some reason my customers seem to like the W124 washers better than my W125 washers so I don't replace the few that I have. But they were very happy when I replaced the w73 with the w75 so go figure. Don't think there is an exact answer to this question.
Gen 4 washer is much better washer than Gen 5,if you check the ad ,most used Gen 4s are more expensive than Gen5.
A lot dealers rebuilt Gen 4 but not many rebuilt Gen5.
I got rid my Gen 5,replace them with Gen 4 since my customers hate them so much.I know a lot Wascomat laundry owner bought Unimac,Ipso when Wascomat stop making Gen4.
Why do you feel that a Gen4 machine is a better machine than a Gen5? Please tell me it is not the frame arguement?
If it is, that is the same arguement they made when cars switched from full frames to unibody construction. When was the last time you heard someones car died because the frame broke. Same goes for the Gen5s, I have never heard of a broken frame on one.
I feel the Gen5 is a better machine as it is so much easier to work on and troubleshoot. Have you ever replaced a timer on a gen4 -- hell of a lot easier on a gen5. Water activated drain valve is much better than motor and gear. Door lock gives no trouble compared to gen4.
I've had the Gen5 units for over 5 years with almost no maintenance needed. Sure they are not built like a 1950's car but what would you rather drive a 2005 car or a 1955 car?
I have both W124 and W125 and customers use the W124's more - but that is an oddity the way my store is set up. The two W125's are all the way in the back while the W124's are closer to the card system and dryers thus customers use them more. But they love all the other Gen5 machines.
I had some earlier model Gen 5,the panel around the door is not stainless steel,it got rust and looks bad,I had a lot problem with the door sw,timer and those parts are much more expensive than the Gen4,I do like the drain.The bigest problem : I could not get my customers to use them,I even charghe them $.25 less than Gen 4,not many people use them,so I sold them replaced with Gen 4.This is like "what is the best washer" question,everybody has different answer.