What is the real major difference with these two pistols? Is the gen 4 worth the extra 50 or so dollars? Any info on this would be helpful.
Here's all the differences Glock Gen 3 VS Gen 4 Differences
One of the first differences people note about the Gen 4 Glocks across all models (even if youíre holding a Gen 3 and 4 that at close glance seem to be very similar) is the fact that the slide is stamped with ďGen 4Ē on it. Another easy way to determine if youíre holding a Gen 4 is to look at the guide rod right below the muzzle; the Gen 4, which uses a dual-recoil spring guide rod, has a larger hole. For those really paying attention, the slide and barrel finish are different between the Gen 3 and 4. This doesnít really make much of a difference, but the earlier Tenifer surface treatment has now been replaced by a similar process that is faster and safer to apply (and is meant to be better for the environment). The metal surfaces of the Gen 4 are of a slightly different color, being a lighter and somewhat duller grey than their Gen 3 contemporaries.
Recoil Spring Assembly:
The recoil guide rod assemblies, as stated above, are different. Gen 3 features a single-spring guide rod assembly, and the Gen 4 has a dual-spring assembly. You can put a Gen 3 guide rod into the Gen 4 if you use the recoil spring adapter (it will not work the other way around). The dual recoil spring helps reduce the felt recoil and also increases the life span of the assembly, because it isnít working as hard as the Gen 3 single-spring. I personally do not find this recoil difference to be tremendous, and since I donít do any competition shooting, I can manage fine with both. Still, any tiny help with accuracy and the reduction of recoil energy to the wrist sure feels nice when you spend a lot of time at the range like I do. Inside the frame, the dust cover features a wider channel to accommodate this larger dual-recoil spring assembly.
The texture on the grip is a little different, with a more aggressive rougher texture on the Gen 4 grip which helps slightly for a surer grip when your hands are wet or sweaty. This new checkering improves your grip and at the same time is still comfortable in long shooting sessions at the range, even without gloves.
The trigger bars on the Gen 3 and Gen 4 models are completely different. The Gen 4 features a rounded bump on the part that deactivates the firing pin safety, though it is still compatible with previous generation guns This bump helps keep the trigger bar centered on the firing pin safety. This also makes the trigger pull feel slightly rougher, and increases the weight of the pull (by an estimated half-pound). Some people really donít like this, though I have never had an issue with it. You can switch out the Gen 4 trigger bar for a Gen 3 if you prefer.
Trigger Housing and Connector:
The trigger housings are different as well, though not drastically different. The Gen 4 has been redesigned to be compatible with the new and smaller frame, and the connector engagement angle is also slightly different. Because of this angel change, the connector features a modified angle to preserve the same trigger pull weight of the Gen 3 pistols. A Gen 4 connector can be used in a Gen 3 Glock, although it will alter significantly the weight of pull.
The ejector was changed in the Gen 4, and can be swapped out between generations. However, it is not sold by itself Ė only with the trigger housing. I donít see any real reason to do swap it out, though, as it functions just fine.
Gen 4 models come with two extra, alternate back straps to help fit these Glocks comfortably into a wider range of hand sizes. The smallest back strap is integrated into the frame, reducing the trigger distance of the standard size Gen 3 frame by approximately .08 in, making it more similar to a 1911. The medium back strap will add approximately .08 in. making it equal the size of a standard frame. Finally, the large back strap increases the trigger distance by a total of approximately .16 in.
Gen 4 magazine release buttons are not only larger for easier releases, but are also ambidextrous, so unlike in earlier Gens, these are now made to be as equally comfortable in right or left handed shooters.
The magazines of both are generally compatible with each other, although if you change the magazine release over to the right-side (for left-handed shooters), then the older Gen 3 magazines, which were built for standard left-sided releases, will not work. The Gen 4 magazine has a notch on both sides, whereas the Gen 3 has only on the left-side (so they are good only for right-handed shooters).
As to if it's worth it, I think it is. But you would have to handle and fire both side by side to see for yourself.