I plan to have the emergency canopy release installed for several reasons:
1) It provides another option in a ditching scenario, and it may help to release both the standard latch and the emergency release to facilitate exiting an inverted, sinking aircraft. One example is if you come to a stop in relatively shallow water near the shore, you have a bit more flexibility in how you push the canopy away from the cockpit far enough to get out.
2) The standard canopy latch and actuation mechanism could be jammed or broken in an accident where there's structural deformation (even if you're upright and on solid ground), and the emergency canopy release handle provides an independent and dissimilar means of escape.
3) I may someday decide to buy a chute and do more acro and/or formation work, so the option to jettison the canopy and bail out will be there if I ever need it...or if the next owner needs it. It might be hard to add back in later if you've filled up the center of the panel with avionics.
4) In any of the above scenarios, the passenger may find it easier and more intuitive to pull the emergency release handle than reach across and use the normal latch if the pilot is incapacitated after an accident. I recall my RV-14 demo ride with Vans at Oshkosh a few years ago...I was not given any briefing about how to unlatch the canopy, and as we were flying out fairly low over Lake Winnebago I eyed the emergency release handle and made mental note that I was going to yank it as soon as the loud noises stopped if we had to make a forced landing.
On that note, I've seen several finished RV panels including the Vans demonstrators that do not have a placard clearly describing how the jettison handle works. Do you pull it? Twist it? Don't assume someone will know how it works in an emergency. Mine will have a placard that says something like 'Pull to Jettison Canopy, Emergency Use Only'.
Spring Hill, KS
RV-8A N2D #80583 - built/flew/sold
RV-14A #140017 - wings complete, empacone in progress...