Considering you asked between factory night sights and Trijicons. I would get the Trijicons all day long. With the Trijicons, you are going to get a sharper appearance of the tritium tubes, a good sight picture, especially compared to Glock or Meprologht night sights, and the front sight is going to be screwed in, instead of staked on like the Glock sights are.
In my opinion, Mepro's are the ones that are overrated. They simply got a good name because they are almost comparable to Trijicons, and lately the Ameriglo's, for people that are willing to accept just a little bit less to save some money. But, the fact of the matter is, if you do some shopping, you can get Trijicons for the same price as Mepro's. They may be a year or or two old, but with Mepro's you never know how old of a sight you are getting anyway because they are not dated anywhere. Not on the sight itself and not on the package. You might be buying five year old sights and not even know it.
I also feel that the Mepro's rear sight might have a greater chance of accidently being knocked or pushed off. When installing the first of three sets of Mepro's that I have on some of my Glocks, they slid on so easily I thought I had been sold a used set that had been crushed into a dovetail before. After doing the second and third sets, it occurred to me that the Mepro's just have a poor interference fit.