I own both, I can post a pic or two side by side if you like.
Personally, I feel about the only similarity they share is the fact they're both a 1/4 inch blade. From there, they're very different in design and intent I feel.
It's hard to truly compare to two because I find them so very different and what they're both good at, but I'll give it a shot.
The Becker is probably the better chopper overall and that has to do with its grind and handle style I feel. It's sharp, but not as sharp as the ESEE-5 if you're comparing stock models. You can get the Becker pretty scary sharp though. Might take a little work, but you can get it there and it holds the edge well.
ESEE-5 is the better cutter of the two for sure in my opinion. The high sabre grind makes a difference here. Also more "pointy" if you will. Again, very different designs.
I like the grip design of the ESEE better. The Becker is fine, but a bit beefy for some people. Doesn't bother me because I've got big hands. The 5 might be a tad easier for small handed people to use over the BK2...grip is a tad slimmer.
The pommels are vastly different. With the BK2, you've got a pretty versatile hammer style pommel. With the ESEE-5 it might be slightly less versatile due to the fact it's designed to be a glass breaker. This is where I do like the BK2 and wish they would make an ESEE-5 without the glass breaker and something more like the BK2 as an option.
They're both very rugged knives. I prefer the ESEE-5 because I find it a tad more versatile overall. But I wouldn't feel ill equipped with either. They're both very good with a great reputation. Really boils down to your own personal needs in the end.
I'll try to get a few pics up if that helps.