Well, at first pass the newer import seems to be much quicker
Import time was 3 hr 21 min 38 sec – but I am inclined to think that the structure and item counts make a large difference.

for a set of books – 50MB
Items on File

Reports 27
Accounts 5,872
Ledger Items 69,914
Distribution Items 23,430
Procedures 610
Printers 23
Notes 72,132

Much better than before when it took a few days. Later I will test some larger books – hopefully with the same kind of results.