If I remember correctly...there are also differences between the Gen 1 and Gen 2 in the other add ons they will work with....like an Extended Mag Release. I have the Gen 2 and also a Magpul EMR and it works perfectly. Unless you plan on adding a specific EMR then I would guess it would be a purely aesthetic choice. For me the Gen 2 wins hands down.

Installation is a breeze, even though Hiperfire (the company) don't recommend putting Anti walk/rotation pins...I have noticed no difference with them installed in my Hiperfire 24C.

I was never worried about my pins walking...never showed any signs of doing so...I liked the look, they really finish off the receiver and the fact that they do stop walking pins , well it's a win-win.