In my opinion an ELT would be useful if you want someone to find your remains in the future after a crash. While spending years offshore on our sailboat we relied on a UHF EPIRB than would alert NOAA and search crews in minutes of an emergency and in most cases lead to a near real time response.
Go with an EPIRB if you are looking at rescue, ELT if you are concerned with eventual recovery of remains.
Sorry, but that's out-of-date nonsense.
Your EPIRB and the 406 MHz ELTs all talk to the very same satellites and notify the same search authorities with the same rapidity and position accuracy. The difference is that the ELT has a g-switch so that it will notify them even if you are incapacitated in a crash, while your EPIRB or PLB will sit by silently while you bleed if you are unable to activate it manually (EPIRBs are automatic only if submerged, so you'll have to crash into a lake to get it to respond automatically). EPIRBs are supposed to be registered to vessels, ELTs to aircraft, and PLBs to persons, but they all talk to the same rescue people. [Registration provides contact information like cell phone numbers for the rescuers to use, and needs to be kept up to date for all types.]
I think some of the responders here are stuck in the mindset from the decades-old 121.5 ELT technology, which was famous for false alarms, failure to activate, low power, and poor location service. The rescue satellites stopped monitoring those in 2009, and it is now illegal to manufacture, import, or sell them in the U.S. You don't have to take a 25 year old one out of your aircraft if all you want is grandfathered legal compliance, but it's just ballast in your aircraft and goes unmonitored. If you buy an ELT today, it's 406 MHz COSPAS-SARSAT, not that old junk. It sends coded GPS location and aircraft identification information immediately to the satellites when activated.
The 406 MHz technology ELTs have been available for a very, very long time (I bought one in 2005) and they provide high power GPS-position accuracy coded signals, with radically better activation rates and radically lower false alarm rates than the old weak-signal homing beacon stuff.