The Ezzo 38mm has a calogen casing causing it to "cup" when cooked. The 41mm Ezzo does not have the calogen casing and does not cup when cooked. If you prefer to have the little cups of grease filled pep go for the 38mm. If you like your pep to basically lay flat aquire some 41mm.
The 38 is a hair thicker than the 41 but not much, if my memory serves me correctly. They both have very good taste. In my opinion, the Hormel presliced is very close in taste to the Ezzo, but I prefer the Ezzo. Basically it boils down to personal taste, but so far of the various peps I have used I like the Ezzo the best. Hope this helps.
Stymie, could you explain what the difference is in the 38 ss and the 38 plain. I'm not familiar with the difference and their web site is down for construction.