I prefer the glued patches too, seem more dependable somehow when I have had some part in their success! I'm sure it's all in the mind.
Regarding your slow leak...last time I had one it turned out to be a valve issue - I only discovered this after taking the wheel off and sitting with the tube and a bucket of water for 10 minutes! A quarter twist on the valve with a valve core tool sorted me in the blink of an eye.
Today I poured some gloop into my tubes - Dr Sludge, a rival to Slime. Time will tell if it works but it's supposed to block flats from the inside negating any need to patch.
Good luck!