For my personal taste, i like them both! Well obviously I've been hearing them and tweaking them for quite some time, and it's not that easy to tell from just a couple of samples! True, they are quite different.
As Xes pointed out, they have the same eq settings, which were Andy's specifical for the 5150. In fact, the Engl clip's tone is different from the one I normally record with, although I don't dislike this tone (a bit too scooped, and maybe a bit too trebly).
Also true that they blend together great, and that's what we're using for our recordings: my tracks will be 2 main Engls with 2 "enforcing" 5150's, the other guitarist's will be opposite.
One thing that I definitely prefer is the fact that the Engl has other 2 channels, and that the midi options (switchable triode/pentode, master A/B, presence A/B etc) allow you to get quite a lot of tones out of it.
After all this, I can't really say which one I prefer, I just love em both!
Anyway, if you want I can post some more clips, with different eq's and gain settings, just let me know. I'll start by setting up my tone... sometime in the near future!!!