I'm thinking of going in for a JLC that's less of a PITA to set, but with a complication that's pretty unique/cool/practical (to me) ... the Memovox. Also, I think the movement would be extra robust* (23 jewels in this case, for the cal. 956) to take the striker/alarm high-freq. vibrations, and a double casing (with sufficient air gap) for a good acoustic "bell-like" chime.
Also, increase in the movement size and thickness to house the alarm striker/striking surface, as also associated "up sizing" of movement plates and other movement components would make it more rugged.
*Edit: I do know it has a larger rotor bearing surface, which makes the movement look visually a little different from other JLCs.
The Master Calendar is visually very appealing, and with the Master Control 1000 hour test assurance, and advances like ceramic ball bearings for the rotor**, free-sprung variable-inertia balance for ease of adjustment, it should be one refined/robust movement and watch (since the movement is the Achilles heel of any mechanical watch)!
**JLC and GP claim that it reduces wear and material erosion from the bearing surface.