I think the 30" is basic to BPCR. 32" is ok, but the 34" is just awkward and subject to fouling out in the extra length. A friend has one and says he would have it cut off, if it were not so accurate. Most of the 28" I see are hunting type rifles.
I prefer the Highwall, and have a real Winchester .38-55 and a Browning .40-65.