I responded to your earlier thread and I understand totally you stay with the EJ's in the signature strat, cause they fit to the guitar. I mean these pickups where the results of a lot of testing and tweaking before EJ was satisfied.
The IT's would sure be a good upgrade for the Classic Vibe. They are miles away form the EJ's and more in the ballpark of Fender Texas Specials. I guess you listened clips and you what you can expect: bitey, gritty, good mids and quite some bass for sc's. Great for clean stuff, blues, bluesrock and rock. Scatterwound pickups are sensitive for height, so if you decide to purchase them, fiddle a bit to find the sweet spots.