I have a Meprolight front sight on my rifle and just recently mounted an EOTech. The truth of the matter is that it's a non-issue.
The key is that with the EOTech, you are focusing on the target. Once you do that, the front sight post gets blurred and tends to move off to the side. If you've ever checked to see whether you are right or left eye dominant, you'll know exactly what I mean.
Hold your index finger straight up at arms length and line it up with an object in the distance (light switch on the wall, etc.). With your focus on your finger, it is nice and sharp with both eyes open. Now close each eye individually. The open eye that maintains the alignment of your finger and the far object is your dominant eye. When you look with your weak eye, your finger appears to move to one side or the other.
Now with both eyes open, change the focus from your finger to the object in the distance. See how it tends to move to the same side as it did using your weak eye? This is exactly what the tritium front sight does when looking through the EOTech.
I am left eye dominant, so when I do the above test with my right eye open, my finger moves to the left. The same happens with the front sight when using the EOTech...it moves to the left. In reality, I really don't even see it unless I'm looking for it.
BTW - CDNN ([url]http://cdnninvestments.com[/url]) has the Meprolight front sight post and detent for $20.
HTH!