I don't own a Glock, but I have heard the new Gen4 is glitchy.
GLOCK Inc. announces that it is voluntarily exchanging the recoil spring assembly (RSA) on its new Gen4 pistols shipped since August, 2009, to ensure each pistol’s performance meets the company’s demanding standards. With several variations of the RSA in the market today, GLOCK’s goal with this voluntary exchange is to standardize the RSA to gain the best possible performance in each pistol.
GLOCK’s product development team has modified various elements of the RSA. The new RSA compensates for all design modifications made to the Gen4 and allows the pistols to function up to GLOCK’s rigid quality standards and reliability goals.
Consumers should note that Gen4 G26 and G27 models will not require a modified recoil spring.
The replacement of the Gen4 pistol RSA can be performed as part of the regular field-strip process; consumers do not need to take the Gen4 pistol to an armorer.