Gunther's booking is weird at times. I remember the Jey/Zayn feuds he seemed almost unstoppable on TV, but lost in an almost uncharacteristic way at the PPV/PLEs.
Beforehand Jey was never known as a submission guy, so Gunther tapping to him at the time felt really random, and so quick that it didn't feel believable. I remember feeling Zayn's win was flat to me at the time too.
Anyway, Gunther has a new submission, and the build (beyond the last match) seems to be submission vs. submission, and that makes sense because Cena's STFU has been pretty protected (especially compared to the FU/AA). However, because it's been protected so much, logically all Cena would need to do is lock in the STFU one time and Gunther should tap immediately if we're being consistent about the whole Gunther tapping fast to head/neck submissions thing.
Another flaw to Gunther is him seeing his own blood and that triggering a flight response in him. I like how they did that when Punk won the belt (before the cash in).
I think it'll be a good match. I'm interested in seeing what they do, because the "never give up" (pass out in submission) ending is almost a guarantee at this point.