I found a supply of American Select for a price I couldn't pass. I decided to try it with 200 gr LSWC in a .45 ACP load. Wow, I'm impressed. This may be my favorite Alliant powder yet. Normally I use Clays, titegroup, or 231 for economy/plinking .45 ACP loads. Right away I noticed that Amer Sel has less smoke (than clays for instance), and burns very clean (much cleaner than 231). It also proved quite accurate with the 200 gr LSWC in my RIA. I've never shot groups with other powders using that bullet that came close to the ones I shot with the Amer Sel loads. Anytime I come up with a load that can shoot a group under 2" at 15 yards (in my hands), It gets my attention. I may have to get another can of Amer Sel if they still have it cheap. Even if the price has gone up, its now high on my list.

I certainly agree with you about all these things, as I've had good results with it also, and if one is concerned with "cleanliness" (I confess I have a hard time telling the difference with many powders) this is as good as anything else out there.

The only downside I can think of is that some complain of relatively large diameter flake powders not metering consistently in their measures, and the flake size of American Select is even a bit larger than Unique, Red Dot, et. al.

So, for them, it would be advisable to not go below 4 grains in charge weight as this prevents the large diameter flakes from possibly bridging a bit in the small diameter cavities. Or buy a better metering measure! I am usually in the 4.5 grain vicinity and above and have no problems whatsoever metering consistently with Select. I most often use the Lee Pro Auto Disk for pistol charges.

In my vicinity the price is pretty comparable to the other powders, so no problem there.

It's unlikely anyone would go quite low in charges comparable to that 4 grain vicinity in 45 ACP, as Select is a bit slower than Red Dot, Bullseye and other fast powders and requires a little greater charge weight, so the problem may be self correcting.

I've never had much of a measuring issue with my Dillon. Even if the charges varied a little, it didn't seem to effect the accuracy. Now if the measure meters so bad the dangerous charges were thrown, well, I would hope this wouldn't be the case. I was using a charge in the 4.5 gr to 5.0 gr range, I can't remember, and don't have my notes handy.
Anyway, it works well for me, I wish I'd tried it sooner, but it was hard to find .45 ACP load data for it. I finally found good data in the current Speer loading manual. Maybe Alliant has added data on their web page? I haven't checked.

Alliant had quite a bit of 45 ACP data for it before they went the ATK route. I can print it if you wish.