Seems like both RM11 and RM4 owners are really happy with their watches. I'd love to get a RM4 but it's way out of my budget - heck any RM is out of my budget these days - and that's why I traded to get my RM11. If money were no issue, maybe I'd get a RM w/ a tourbillon but I would probably buy both the RM4 and RM11 since each has itsr own quality and functionality.
I absolutely love my RM11 and it's the one that gets the most wrist time these days. I used to wear my PVD Panerai everyday, but the RM11 has replaced it and that was for sure a tough watch to beat as my main wearer. I really love the annual calendar and big date features, but for me the 30-min countdown timer at 9 o'clock is absolutely useless because I can time 30-minutes with the chronograph. Furthermore, the chrongraph minute hand moves in tandem with the 30-minute countdown hand so I'm puzzled as to why there's even a 30-minute countdown register. I'm not that familiar with F1, but is there a 30-minute significance with F1 racing?
Anyways. if you are comfortable wearing large watches - I mean really really large watches - then you'll love the RM11 because it's thick, huge, but surprisingly fits like a glove on your wrist, even if your wrist is small. The slightly curved case along with the strap angling straight down from the lugs makes the RM11 suitable for all wrists greater than 6.5" IMO. The only drawback I've found with the RM11 is the super thin strap it comes with and lack of various strap choices. People in this forum have mentioned the rubber strap for the RM11 is available, so I'll probably try one of those in the near future.
If you're not comfortable wearing an IWC Big Pilot, 47mm Panerai, or AP Offshore, then I'd definitely suggest getting the smaller sized RM4.
Cheers,
Anthony