It depends when they were made. The earlier Smiths (maybe including your 36, depending on when it was made) oftentimes had smoother trigger pulls than the newer models. I wouldn't worry about this too much though. The 442/642 are acknowledged by many experts as among the best pocket guns and/or CCW pieces out there. You can always get the trigger slicked up a little.
I would buy the 442 without hesitation and of course keep the 36 if you can. In addition to being lighter, the 442 is a better pocket gun because there is no hammer to snag on your pants when you draw. I do NOT like the hammer on the 36--you don't want to ever use single action in a self-defense situation or be accused by a prosecutor or plantiff's lawyer of accidentally firing in single action. You can always bob the hammer on the 36 (or like I did with the 60 I carry, drop in a factory-bobbed replacement hammer so you don't have to chop up the hammer) or get it made DAO.
So I would buy the 442 and not worry about the trigger. Then get yourself a Mika's pocket holster or Desantis Nemesis pocket holster and carry away!