Good question shawn ...(thank u mike. I had to read question a few times for it to sink into my thick skull).
I remember John going into detail before I authorized work. He assured me more surface area and more heat than OEM. Sales ploy? Perhaps.
He said the rebuild would require more then 100 foot of 3/8 copper tubing rated at 1500 psi +.
He also said copper transfers heat better than stainless.
My gut was to have
AT build it but TM was already down two weeks + before Johns informed me it couldn't be repaired.
AT's lead time was longer so I went ahead and let John do the build.
From start to finish
AT probably would have taken same amount of time or less.
Jury still out on wether Johns E-1 is
superior to
AT built. Maybe u can enlighten me.
Hope this helps.