The new ones tend to be tight. The only difference with the extended ones are they stick out farther, they are easier to engage. I have them on all my glocks, they are a great improvement over the stock mag release, especially if you shoot IPSC. The spring that holds it in place is the same regardless of what size mag release you use, it will soften with time. If you are familiar with breaking down a glock into parts, installing an extended mag release is a three minute job.
If you keep yours stock, don't worry, it will loosen up with use. Get out to the range and use it!