We've always let our Siamese cats out - as my parents did/do before me. :)
It was a major factor when we were looking for a new house - had to be in an area quiet enough for cats. Estate agents really didn't get it: "But there's a big garden" and/or "The house is set back from the road" might be OK for kids but not ok for cats 
We nearly didn't get our first pair of cats though, as the breeder rang us concerned, telling us that one of the other breeders we had visited before deciding on her cats had been ringing around the breeders telling them not to sell to us because we were "unsuitable"
Turned out it was a) because we had said that we refused my parents' cats (who had been staying with us) access to a litter tray (not true - they were used to going outside and we had moved the covered litter tray into the close and then outside to get them used to the area) and b) that we lived on a main road. This one had used stumped, "...but, but, we live in a dead end road"
- until we remembered that I'd mentioned that working in Ayr and living in Glasgow wasn't a big problem because we "lived close to the A77". Now "close" is relative in cat versus human-in-a-car terms: the A77 was 4 streets away, with tenements in between 
Foortunately our breeder was prepared to listen to us although they did insist on delivering the kittens themselves and has since sold us two more Siamese (the original two have died). :) We've become friends and visit each other every so often (although she is up in Aberdeen, so a fair trek).
Ironically, the reason we hadn't bought from the breeder who "raised the alarm"
was that we hadn't liked the conditions that she was raising her cats in: about 14 cats in a very small house, scratched wallpaper everywhere 
We do microchip our cats though! :)