I have a tritium Troy front sight on one of my ARs. Troy makes good stuff and it's a good sight. It set me back a little north of $100. I would consider myself to be a fan of most of Troy's AR products. I do believe in their product.
All that said, I regret purchasing this sight. The night-site feature really isn't all that practical on an AR from what I've seen. Mine still sits atop that rifle (and I may keep it), but I'd have probably been better served just buying a $40 Magpul flip sight.
Your mileage may vary. It's not a bad product, but not ideal for me at least. If you want one, you might be able to get mine (bought a couple months ago, sitting atop a not yet fired rifle) for a very reduced price.
But my advice is generally going to be Magpul MBUS. Affordable, light, durable, functional.