The roundcase twins seem to be the most desirable but collectors of singles and twins don't usually agree.
The twins bring more money.
Roundcase bikes were built in 72 73 and 74. Some Roundcase bikes were made available in Australia in 78.
ANY of the roundcases are good bikes to collect and are increasing in value.
The most valuable and most desirable Ducati of all time is the roundcase 750SS.
There were a little more than 450 of them made in 1974.
Some Ducatisti who understand the history believe the 750 SS is the worlds most beautiful bike.
I love it but I'll take my Tricolore as the worlds most beautiful