I too am a fan of the 3.5# connector and the NY#1 spring. I have it on all my Glocks, even the one that is sort of for competition. having started my LE career with a DA revolver I prefer the more revolver like feel of the above connection.
You can purchase this combination of connector and spring as genuine Glock parts for about $27 from Glockmeister. I've found them to be very good people to do business with.
RSVN Oct '69 - May '71