Yeah, I think Otter has a higher upside, no doubt. Can't see the need to insult or demean someone who thinks that.
The only way he doesn't is if you already have his ceiling very high, so that in your mind, he can't get any better than what you expect. If your definition of upside presumes both are quality prospects, and upside means the relative rank they will actually attain at their respective positions, I still think Otter would win. IMHO, he will be nearly as good as Bishop when he hits his prime and Guri will be a mid level second line, one dimensional scoring FW, with some defensive warts. Yeah, his speed will generate some exciting chances, but there isn't conclusive evidence at any level that he can bury enough of those to be a top, top line forward. Nill seems to have drafted for speed and figured they could teach him to shoot better (similar to the Val pick). I think most teams would draft based on what they have actually accomplished at lower levels.
Of course, just MHO. I believe Otter will be very good, something it doesn't seem many posters here agree with. Maybe its the JC pick, the general idea that first round goalies are a crap shoot, etc. For all our sakes, I hope Otter is everything they think he can be.