There are two types of biceps muscles depending on the tendon attachment - long and short. The example below shows the natural bodybuilder Lui Marco who is a prime example of long biceps tendons.
As you can see there is a gap between Lui Marco's biceps muscles and elbows. The reason for that is the longer tendon inserting at the elbow joint. The main benefit when having similar attachment is that the muscle "pops" more and usually has a better peak. However it also looks smaller and less "fuller".
Another example of short biceps is the legendary Albert Beckles:
Here is an example of short biceps tendons as well.
In case you don't know those guys are the hodge twins. They have long biceps and you can see that there is no gap between the biceps muscles and the tendon. The benefit of having similar bicep insertions is that usually your arms will grow faster since there is more muscle fibers to grow. The situation is quite similar when it comes to calves. Technically the only disadvantage of longer biceps is usually the lack of peak as presented in the picture below.
Sergio Oliva had long biceps and no peak.