If you're experienced at soldering you can probably tell when the connection is good - but the majority aren't that experienced. With a proper ratcheting crimper and the right connector you get a true cold weld inside as Mainesail's pics above show very well. Even for battery cables if you use the FTZ 94285 crimper you get a true cold weld in the lug. I just finished a set of battery cables in 2/0 and it worked like a charm.
I understand why you'd crimp when the conductor can't be replaced easily but I would crimp and heatshrink 100% of the time.