Following prior iPhone launch traditions, Apple has offered a handpicked collection of reviewers early access to the Verizon iPhone 4, embargoing their reviews until this morning. Their conclusions are collectively mixed, focused on four primary differences between the AT&T iPhone 4 and Verizon CDMA version, and wavering on the wisdom of making a purchase now. Data Speeds: Virtually all of the reviewers agree that Verizon’s data speeds are…