A commercial loan that requires 20% down is already an achievement in some markets. Some lenders require a 25% down, so I think that segment of your deal looks great. The only problem I have is the 5Y adjusting rate; are you sure that its not just a 5Y ARM rather than locking in for 5 years then locking for another 5 years, etc.? Btw, a 5Y ARM typically would adjust after the 5th year and lock annually depending on Libor or another benchmark rate.
As a borrower, thats an insanely sweet deal in my opinion if you are correct about the loan structure, because you are pretty much hedged everywhere - i.e. you'll only face minimal interest rate risk, and even then you can refi- out if the rates too high.
As a lender (and professionally I'm in investment banking), I've never seen that before because it sounds like a terrible deal for me. I will say though, that this world is huge, and there are brilliant people who are smarter than me and may think these are great lending terms (perhaps they can trade/sell this elsewhere after they originate?).
In conclusion, I think you have to make sure to understand what the financing structure looks like. You have to also make sure that if its a 5Y ARM, thats its a 5/1 and not a 5-6 or something crazy. Make sure you understand the monthly and overall costs. And also, do more research and see if you can get an even better rate! Good luck friend.