Jeff,
In my experience E-Tips are somewhat like the original Barnes X-Bullets, before the shanks were grooved to create the TSX: They're more sensitive to exactly which bores they'll shoot in, probably due to matching groove diameter closely.
That said, I'd guess E-Tips have been very accurate in 85-90% of the rifles I've tried them in. Sometimes you have to dink around with seating depth (deeper often works better), as with TSX's. But in barrels that match up well, they're just as accurate as TSX's, with a higher BC.
