What is an 'ultimate crisis' .45 pistol?
If you mean a service-type defensive pistol chambered in .45 which is reliable, durable and relatively easy to maintain in the field, then I'd easily choose a 1911 made to the proper specs, made of good materials, fitted for service use (meaning not target use) and combined with proven, good quality magazines.
Picking a 'high end' 1911 wouldn't be something that would occur to me, though. I'd be satisfied with a good quality basic model that functioned as intended using reasonably good quality ammunition and magazines. What more is needed? (Well, okay, some better sights isn't a bad thing.
)
Now, being a Colt Model O Pistol armorer ... and a long time owner, user & shooter ... I'd lean toward a standard 5" Government Model that was properly manufactured & fitted from the beginning. The last couple of brand new 1911's I bought both fed & fired all of the various JHP/FMJ ammunition I've tried in them, using a mix of at least 3 brands of good quality magazines. (One uses a pinned extractor, though, and a bar gauge is needed to check the fit of any replacement extractor, so it really isn't as 'easy' to replace for field repair as a standard internal 1911 extractor.)
I've never bothered to become a HK armorer, but I know a couple of them. The design and number of parts in the HK guns seems to make for a bit more complexity than the typical 1911-style gun.
And yes, I've personally observed a HK USP 45 start exhibiting problems for an instructor during a class ... listened to the HK armorers complain about functioning problems caused by their people not sufficiently lubricating their USP's ... and spoke with a fellow who spent a year overseas in the sand and had a chance to do some shooting with both a standard USP 45 and a Mk 23, both of which were quickly adversely affected by the very fine sand as far as the safety levers not properly functioning when contaminated by sand. (But hey, what mechanical equipment
does like sand?
)
My point is that I'm not under an illusion that any make/model of handgun can't fall prey to occasional problems, especially if called upon to function in adverse or harsh conditions, and would prefer a gun which is easiest to support, maintain and repair in the field with common parts.
Capacity is less of an issue for me than other considerations. I carried issued .45's with mag capacities of 7 & 8 rounds without any qualms.