My view is the best way to obtain potentially good pigeons
is to buy birds from a winning family of pigeons - and it doesn't
make any difference if the source is a racing loft or a non-racing
stud.
A winning family is one in which the winning genes occur
generation after generation - in sons, daughters, uncles, cousins,
half brothers, great aunts; you name it.
The best way to keep such a winning line going is by inbreeding
around the champions, and some studs do this well. It doesn't mean
that every pigeon bred will be a champion but a high proportion will
have the right genes and could be champions if managed well.