Congrats on the crazy cycle bro!! Proud to see your hard work pay off!!
My mentors (primarily high-level academic physicians, for transparency) have pretty much hammered these four aspects into me when considering where to attend: Finances, prestige (within medicine primarily), stress-free curriculum (No AOA, P/F for pre-clinical + clinical), and your "fit" with the institution (i.e., choose the school that maximizes these four aspects for your personal situation).
Based on these factors, personally, I would lean heavily towards Wash U, especially if you see yourself going into private practice (though, would also suggest Duke if they match the scholarship). Minimizing the financial burden of your medical education is a significant pro that not many people have the chance to experience. Attending a T5/T10 with little debt is HUGE.
(For context, my mentors have said T5s/T10s are absolutely worth ~$200k in debt - any cheaper great, any more than that, look for cheaper alternatives that still maximize the four factors above)
However, I do also have to say that my "lean" would be modified if you had a change of heart in what you wanted to do as a physician (which, IMO, is very, very likely to happen - just chat with a couple of seasoned physicians and you'll see what I mean hahah).
That being said, I also feel compelled to mention this. IMO, I feel Harvard would be the school that leaves the most doors open post-graduation. Would I personally recommend that you attend Harvard for $400k-$500k? Honestly, I really don't know if Harvard is worth that price tag, because that much debt will absolutely affect your QoL as a physician. I would fill out the financial aid information for Harvard ASAP and see how much aid they give. You might be surprised at what you receive!
All in all, you really can't go wrong with your options (it's what all my mentors tell me about my cycle, and it's so true hahah). One piece of advice that I also ascribe to is to make a decision based on what would leave you with the smallest "what if". I couldn't tell you what that may be for you, but think about what option would leave you with the least regret!!