I'd need some wrist time to be sure, but it's a hard one to fall for immediately. For me at least, I like unusual case materials and dials but my taste in cases themselves is quite classical and perhaps even a bit unadventurous. I wasn't immediately sold on the third generation "barrel" Carreras but have gotten better acquainted now and like them more - they share some similarities with Mark III Speedies, having covered lugs and being quite thick. It's the case "extension" on the MIII over the lugs though, doesn't look right to me. The dial layout's not my favourite either.

In fact, I'd probably put it after the Moonwatch case, the MII and MIV close together and the German MVs in terms of my favourite Speedy case. Same with Zenith el Primeros too, I prefer the models with distinct lugs. The early 2446 Autavias to 1163, 11063 or 11603.

That's just my personal taste though, I nonetheless enjoy the fact there is so much diversity in the cases. If I ever open the gates (I fear they would be floodgates) on a Speedy collection, I'm sure I'd want at least one representative of the Mark IIIs. Just as I'd want an X-33 in there too. My collecting tastes encompass both the subtle differences like Jeff's four black-dialled Autavias recently and the more strikingly different too. Despite all my Heuers being Carreras :)