Had my combo I-751 / N-400 in Philadelphia. Everything went fine - took less than 10min.
Don't recall all questions but once you invest a little time in the 100 potential Questions they could ask - I think everyone should be fine...
Not it's time to wait again for the Oath Ceremony - looks like a late June / early July timeframe.
At least the journey is 99% over and all that's left is a formality