The Bianchi X15 is still good, even though they've added extra retention straps to hold the gun in place that really aren't needed.
A really great holster is now made by Nevada Holsters.
This is a close copy of the old Hardy-Cooper holster that Jeff Cooper had a hand in designing.
What makes this one one of the very best vertical shoulder holsters is the way the toe of the holster is held by the belt.
Unlike most holsters that have a strap on the back that snaps under the belt, this one has a slot in the bottom toe of the holster that holds the holster much flatter against the side.
Since the holster is held firmly flat, this allows not having the leather harness covering part of the gun butt.
To work right any combat holster of any type reeds to be clear around the butt so you can get a full shooting grip on the butt BEFORE even starting the gun out.
Done properly you can grip the gun, draw it and never have to shift your grip at all.
Many holsters, especially vertical shoulder holsters have leather covering part of the butt. This requires getting a partial grip with a couple of fingers, starting the gun out, then having to juggle the gun in mid air to shift your hand to a shooting grip.
That causes slow draws, fumbled draws, and even dropped guns.
The Nevada Holster take on the Hardy-Cooper design leaves the entire butt clear, but due to the toe mount to the belt the holster lays flat on the side of your chest and the butt doesn't stick out like a sorer thumb.
The original Hard-Cooper:
Nevada Holsters near-copy:
http://www.nevadagunleather.com/Springclip-Shoulder-Holster-156.htm
Another very good one is the original "Dirty Harry".
Unfortunately, the reputation of the makers really stinks badly.
They claim the "bad guy" was Lawman Leather, and that they aren't connected, but I'd do some serious research with the gun forums and the Better Business Bureau before risking a dime:
Current ??? maker:
http://wildgunsleather.com/
"BAD guy" maker:
http://www.lawmanleathergoods.com/