Lumpy, you forgot to mention that the tritium front sight is also wider and subtends more of your target. Not a problem up close, just not as precise at distance.
We just switched to the Trijicon's on over 100 of our M4A1's and they take a little bit more effort because they are as wide as our 100 yard target. Also we have had to zero these sights near dusk, and the darker it got, the harder it was to obtain a true zero because of the POI change Lumpy mentioned.
With that said, if you don't have optics mounted they're not bad.