The problem with inertia reels is that, deep down, we really don't trust them to work....search your feelings...sorry, I just watched Star Wars for the first time in ages on HBO. Okay...I have this somewhat deep seated problem trusting them. In my Luscombe I too opted for the inertia reel on my side and the slap-you-to-the-firing-squad-pole on the other side. As a part of my Luscombe pre-flight I lurch forward to see if the damned thing is going to catch me
In short, inertia reels are cool, even if you don't need to reach for something. Our triple tails can cover a lot of ground and being able to move around adds more to comfortable range than an Aux tank. If you have the money - and I know it's a LOT of money - install a reel on the copilot's side as well. As for the rear seat passengers the law states that they only need to be buckled up during the take-off and landing phases. Plus, if the end of your flight is...uh...extremely sudden, their heads hit the back of your seat, not a metal panel.
I don't know about you, but when I fly in the right seat, or have someone in the right seat, it's usually a pilot who helps out in various ways such as grabbing the next sectional or approach plate, calling out the ATIS and AWOS frequencies enroute and so forth. I regret not putting on reel on the copilot's side in my Luscombe. When I upgrade to shoulder harnesses I will put reels on both sides.
Yes, copilots can loosen their belts or apply the same rule as "passengers" but a recent encounter - at altitude - with wake turbulance, as I described in another topic, changed my thinking on that when it comes to transitioning through major league airspace. The worst of it is not, as previously thought, to be when those gigantic thermoses with wings and jet engines are dirty and on final, but when they are clean and flying slow...well...slow for them.
Now I simply have to practice what I suggest
Jonathan