I have the Crawler/Irish Tours-combo in a swampash-strat. Does everything, but metal, but I don't play that anyway. Crawler spits very good too. This pickup is great to fatten up strats. No whimpy leadtones anymore. It's a sort of very hot PAF, but nothing over the top. Sounds good on any of my amps.
The Irish Tours are great for funk, pop, rock, bluesrock en rock. They are fuller and grittier then Mother's Milk, but if you turn the volume on the guitar a tad down, you can get close to Frusciante-tones. The neckpickup is great for soloing. Slowhands are quite middy. If the second and fourth position are not that important, you could put an IT in the middle and a Slowhand in the neckpos. for more versality.
My ash Fender American Series HSS has a VHII/Mothers Milk-combo. This set is a bit leaner then the Crawler/IT-combo, but great on a good amp. VHII is balanced, but brighter then the Crawler. Great touchsensitive rockpickup. You get punch and nearly no compression. Screams when driven hard.
I did not only swap the pickups, I took out the S1-switchingcircuit. I went for a simple setup with autosplit on the fourth position. Swapped the pots for cts's. This strats sounds so much better then with the original S1-system/pickups. Really breathes now.