Explain why I would want one over another similarly-priced scope. The two models I'm considering are the TR21 and TR24.

My only hold-back is that I believe in buying once and paying once. I take care of my things (and my guns), so I have no doubt I would keep the scope for the next 15+ years. The idea of having to pay to recharge the Tritium doesn't sit well with me, nor the tiny chance that the scope might become obsolete and therefore not rechargeable. Again, I just don't like buying something that I KNOW will fail without use over time. It's not the money, it's the principle of the matter.

The other optics I was considering were Aimpoints or similar priced performing scopes (though I honestly don't know of too many that can compete with the Accupoint for their price).

Thanks =)

The tritium only comes into play in low light situations. Any other time the fiber optic makes the reticle very bright. I have a 3-9 and its easily my favorite scope. Very fast onto target at the low end, and very crisp at 9x. The only time its a bit dim is in a dark area looking into day light - the fiber optic doesn't collect much light, and the tritium can't compete against the daylight.