They're all good drivers and you can't go wrong with any of them. It just depends on the install locations that will be used, and the other drivers that they'll be paired with. The 12MU is the top dog out of those IMO, but again, I think you'd be blown away by any of them if they are installed and tuned properly.Its a toss up between the AF GB 25 or 40 and the Scanspeak 11M or 12MU
Before I saw your last post I was going to suggest these Scan-speak 10F drivers that were OEM'd for Thiel. It looks like some are still available at Madisound for $53 each. Quite the deal. Link in the following thread....
HOT DEALS - Scanspeak/Thiel 10F
EDIT: Was typing while Nick posted his thoughts. I concur, but I did at least mention that it was location-dependent and enclosure-dependent.