As I am getting near the end of the series, there are a few points that stand out for me.

One is that in the first two seasons, Drake used more of his inventiveness to solve the problems. In the third season, he relies more on gadgets (which I think is due to the influence of the James Bond films on the series).

I am a bit surprised at how smoking and drinking are nearly always present in every episode. I am uncertain if this is due to the times the show was created in, a choice of the director or at the sponsor behest.

Every time anyone enters some one else's place of residence, they are offered a drink, which is always some type of alcoholic beverage and it is nearly always accepted.

And most of the character's smoke, and deny anyone the opportunity to smoke. (Of course Drake has used this in several situations to his advantage). This point stand out to me, as I was reading up on the original Star Trek series, and Gene Roddenberry insisted that no one smoke in his future world,(though he himself was a smoker) and that that caused some irritation with the sponsors. But it seems logical now (no pun intended) but it shows how forward thinking Gene Roddenberry really was.