Hi Paul.
Hopefully I can give you some information that might help you. I am from the UK but I did live in Arizona for a year in 3 different houses. So I used 3 different types of washing machines. One of them was a Whirlpool pretty much the same as the one you are considering.
I found that the Whirlpool had had an Energy Star makeover. I had to set the rinse selector to "fabric softener added" for it to do a deep-fill rinse. Otherwise it would rotate the tub slowly while filling about a quarter full with water, then draining with no agitation. Selecting "fabric softener added" along with second rinse would only do the first rinse as a deep fill and the second rinse would be as previously described unless using "Super Wash" in which case they were both deep fill.
Also the temperatures were interesting -- I measured them. Options were cold, cool, warm and hot. I found that if using "super wash" then the hot temp was 50 °C. If the incoming hot water was any hotter then it would add cold and would not go over 50° unless you shut off the cold water valve. Warm was 40 °C. I don't know about cool and cold. However if using the regular wash cycle (not Super Wash) then hot was 40° and warm was basically cold (30° or probably less).
Cycle times on this machine were longer than traditional American TLs. I found that Super Wash with a second rinse was close to 90 minutes. The actual wash portion was 20 minutes of agitation. The other hour or so was filling, draining, rinsing, spinning etc. This machine seemed to fill strangely slowly like the value was partially closed and would take about 8 minutes or more to fill up, but water pressure/flow at the sink was normal. But that could have just been this machine/house. You could use the regular cycle (select HOT to achieve WARM 40 °C) and set the rinse selector to "softener added" and you will get one deep fill rinse. This cycle might be about an hour or so.
Also, this machine didn't work like a traditional American TL with the transmission, clutch and brake. There was no brake. The lid locked until the drum coasted to a halt. The motor basically just pulls the agitator back and forth as the motor continuously reverses direction. This sounds quite different to the traditional type were the motor runs constantly and the agitator's direction is reversed through the transmission.
Having said all that, results were pretty good. And the temperatures were consistent, thanks to its ATC. So if you are just interested in the end result, then the laundry will probably come out pretty similar to laundry washed in the Speed Queen. But personally if I wanted an “American” TL then I would be a little disappointed with this machine because it has lost its “Americanness”. I don’t know specifically about the Speed Queen model you are referring to, but if it’s anything like the American AWN542 then I would DEFINITELY go with the Speed Queen. Although the AWN542 has had its max fill water level reduced slightly, that can easily be “corrected”! And you check the ratio of hot & cold water going in on “Warm” to make sure you get the desired temperature, even if that means enlarging its hot fill valve. The Speed Queen should also be made very solidly and will work the same as a traditional American TL (if it’s the same as the USA models).
Let us know what you decide to do!
Mark