If your Gen 2 has the upgraded parts it is not inferior at all to the Gen 3 or Gen 4. A lot of people will argue that it is better.
I recently got a like new Gen 2 G19 and the only thing that I needed to upgrade was the slide lock spring (it had the old style narrow spring). It and my Gen 2 G20 are as good if not better then my Gen 3's and Gen 4's. I personally like the non grooved grip on the Gen 2.
Gen 4 - 17, Gen 2 - 19, Gen 2 - 20, Gen 3 - 22, Gen 4- 22, Gen 4 - 23, Gen 2.5 - 27