The sizes of the TT1958, TS and UT all seems so well-suited for what they are.
TT1958...just perfect at a modern 38.5mm...could have gone up 1mm, but beyond that would have lost charm. Just fine, and very wearable at 38.5mm, which looks bigger given its white, open dial.
TS...within the close range of my overall favorite size for a watch (of this style). Lose the date (always the same comment with me!), or offer a date-less option, and it's a winner.
UT...another good size, that wears smaller than it's size measurements would imply given the gradation of colors (darker center, then lighter outer rings...the eye focuses on the darker center making the overall effect seem a bit smaller than it really is). That said, I might prefer losing 1mm on this one for overall comfort and wearability, but I would have to see the end result to be sure that the UT's beautiful dial and city/time rings work as nicely as they currently do.
The tourbillon? A big statement watch that probably deserves its diameter (although ca. 15mm in thickness is too much IMO). Thankfully, JLC didn't go crazy and thrust a 45-47mm diameter behemoth on us like some watch companies would have done. I hope to see the tourbillon in person at my local JLC boutique at some point.
Cheers,
John
(Who is very much looking forward to the continuation of the Geophysic line of watches, and, hopefully a true sports watch within the lineup.)