I have the Crawler in a swampashstrat and it delivers the goodies for me. A huge sounding pickup that cleans up very well. More PAF than modern sounding. You could see the Crawler as the Uber Mule. But, it's not a very bright pickup. The topend is round, yet not dull, however not as present as the high register of a VHII.
The VHII is a different animal: noncompressed, dynamic, focussed and very touchsensitive. The Crawler has more compression and softer bass. You can really steer the VHII with your pickattack and let it scream when you dig in. It has quite some some bass for a vintagehotpickup.
Both great pickups, just different. I have both in strats. The Crawler sounds bigger than the VHII. The VHII delivers harmonics/overtones easier. They just jump out.
I have Irish Tours paired with the Crawler. Great pickups: more bass and mids than the Mother's Milk, a little less glassy. Once you turn down the volumepot a tad you end up in Mother's Milk-territory (tones like RHCP by example). Does SRV with authority too.