Well that is true. I personally have come to the conclusion that n400 interviews are generally not that much of an issue. As long as you have not spent 6 months out or longer & as long as the intent is to be a PR - honesty is the best policy and will win the day, if not - through the honest approach you get the chance to fight another day.
Maybe this is for another thread, however some of the attorneys I have spoken too have not made a conclusion if the ''look back rule'' 5 yr requirment (with 2.5 yrs in the US)...
1. begins the date of gaining the card
2. is from the n400 application date backwards
3. or is from the date of the interview backwards
By travelling heavily in the later years of your application - the early years of residence will be eaten away if the IO takes the 3. approach. (If you get what I mean?)