Personally, I believe that standard check-lists which work across several types are very useful.
The Super Cub I used to fly didn't have retractable undercarriage, but I still used to call out "undercarriage down" as part of the check-list. Now I fly a Europa, and I use exactly the same downwind check-list as the Super Cub, including "undercarriage down". I also call out "mixture rich" and "carb heat on", even though my aircraft doesn't have a mixture or a carb heat control - but by not dropping them from my check-list, I know that I'll be able to move to other types and still use the same check-list.
I used to occassionally start the Super Cub without using a check-list - only ever when I was taxying it, not when I was planning to fly it. I have to admit having forgotten the odd item or two once or twice - I think I forgot to turn the master switch on once, and forgot to prime it once. No big deal when taxying, but I certainly wouldn't recommend it for flying. All you need to do is forget to set the trim for take-off, and then stall as soon as the aircraft has enough speed to lift itself off the ground, and you'll regret it
Someone's gone to the trouble of preparing these things, so why not use them? IMHO.
FFF
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