Where the sideburns end ...

[Razor X]

If I trim my sideburns to the length of the rest of my beard, they look bad because it looks like my beard starts with a dense puff of hair at the top of my ears.  Also, the hair at the top of the sideburns is scalp hair and not beard hair so when it gets thick it looks totally different. 

That's exactly what I've been experiencing. 

The beard suits you, BTW.  I like the lower neckline/jawline on the current version. 

[Slynito]

I have a mole that I've sliced many times, so I keep it covered with beard.