What interchangeable means is that The firmware from Hikvision USA and Hikvision Europe is interchangeable. What is NOT interchangeable is firmware between models and revisions. Not all 7600 series recorders are made equal. The SE revision is an older recorder that, from the guess of recent firmware updates, is slowly being killed off. The "E" revisions are all current and the latest Hikvision offerings. Your best bet for long-term support in terms of camera future proofing is to exchange it for an E2 model. (It just got a firmware update a week ago, for example). I have both recorders and can personally attest to the SE revision having older, slower hardware. It takes forever to boot up. Two major changes between the SE/SP revisions and the E revisions is the elimination of all BNC connections, and the upgrade of the rear USB port to USB3.I recently purchased a 7608NI-E2 however just noticed seller sent a 7608Ni-SE
since firmware is interchangeable is there any reason to return the unit and get the E2.
between the 2 firmware is the E2 preferred over the SE or visa versa.