I had a Brooks Swallow on my De Rosa with about 120 miles on it but just replaced it with a used Brooks Swift with titanium rails I bought off EBay a few weeks ago. I put 33 miles on it last weekend and it has a different feel than the other Brooks saddles I own. I have a Brooks Imperial with 250 miles on a Trek 760 that gets 20-30 miles/month. I’ll only be putting 30-60 miles/month on my De Rosa with the Brooks Swift so it may take a while for the seat to re-conform but I think I’ll be happy with buying used. The saddle appears to be fully broken in and gives my bike a more vintage appearance than with the newer Swallow saddle.
I don’t ride my bikes with the Brooks saddles too often so it may take me a while before the other saddles are broken in, but the Imperial saddle on my Trek 760 is already pretty comfortable after 250 miles or so.
The Swallow was on my De Rosa but I just swapped it for the titanium Swift.
The used Swift appears to be in good condition and was pretty comfortable on my first 33 miles on it.