I wouldn't be miserable but I'd probably be a little disappointed. Harris is by no means a "corporate Democrat" or a centrist, but I don't find her to be particularly bold or visionary. These are traits which I find important in a leader. Harris is just so milquetoast to me. I'm in no way offended by her presence, but I feel like she lacks a strong message at the center of rhetoric. She's not as charismatic as Clinton or as good at speaking as Obama. She reminds much more of John Kerry, utterly boring. This fact is especially clear when you consider that Democrats have much stronger options on the bench.
The other big problem I have with Harris is her experience. By 2020 she'll only have been a Senator for four years, the same as Obama. Obama did a lot of great things but ultimately his success was hampered by a lack of experience. After having eight years of Obama and four years of Trump, I'd really hope our country would unite around someone who really knows what they're doing. I much prefer Governors to Senators anyway as presidential candidates. Harris' lack of experience makes me worry that she'll have trouble passing any meaningful agenda anyways.
I,d never use Harris and Kerry in the same sentence. Harris is nothing like Kerry not even close. She is a lot warmer and personable. She is no Bill Clinton or Barack Obama. Clinton and Obama are rare kinds candidates.