I have read this on a website, I will try to locate it, if I cant find it again, im sorry... this was when I was looking for someone to refinish one of my guns.
Their is a gunsmith that only uses Mepro's. The reason he gave was that when he only used Trijicon's, and had trouble with 1 here and thier, Trijicon was a real hassle to deal with for a return, something like if he had bad sights, they were installed wrong/mis handeld. After switching to Mepros, when a defective one would come up he had no problem returning for a new one.
I for one like the Meprolight sights, They DO glow brighter than the Trijicons. I was able to see both the Trijicons, and Meprolight sights on a Glock 26 & 27, I was going to go with the Trijicons originally, their "the best" right.... well when the mepros glow was brighter, and the Meprolight was cheaper, and the warranty was right, Plus the good reviews, I went with the mepro's
I dont think you can go wrong with either one though, both Meprolite and Trijicon are licensed by the NRC to manufacture tritium tubes.
**EDIT**
Yes, Meprolight sights have a warranty of 12years.