E3 is a terrific powder, clean as advertised, and like everyone else, can't find any and I have been searching. There are some 1# containers around if you are willing to pay the price. I like it a lot, just not that much.
I have found it very satisfactory for 7/8~1oz. loadings. Just finished the last 8# canister on hand and would load more if I could find it in that size where I didn't have to fool w/hazmats and shipping costs, but I cannot. I would not hesitate to use it again; it is a good clean burning powder. If it is available to you now at a reasonable price, I would say buy it and don't look back, its good powder for target loads.
When I tried e3 several years ago (DuPont\IMR still owned 700X) it was IMO a clone of 700X. Good stuff, but pricey. Didn't buy any more stayed with 700X until I couldn't get it, switched to RD &\or Promo. Haven't tried 700X since Hodgens acquired 700X, have heard that it's different now. Ross Puls
I use it exclusively for skeet. 3/4 oz 15g of e3 or whatever the #28 mec bushing drops in GC hulls. Its very clean in that receipe or even my 7/8 loads but I use Titewad for those now which is also a clean burn. e3 is as stated a tad pricey though. If you got it use it. You'll like it.
e3 is now the only powder I use for 12 gauge Trap loads from 7/8oz through 9/8oz. It is extremely clean, meters very well, has a low flash, and exhibits absolutely no temperature sensitivity. A little goes a long way, and that reduces recoil. I also use it for my USPSA 172PF Limited load. It performs superbly in 40 S&W. Now that I have a reasonably good supply, I also use it for my 45ACP bullseye loads under a 200gr SWC. Very accurate.
The remaining Clays, Clay Dot, Red Dot and 700X I have sitting above my reloading bench have been there for a while. I bought the 8lb of Clay Dot when I couldn't find any e3. As soon as I did the CD went back on the shelf. I probably should take it all to the club and leave it for anyone who wants it.
Over the last couple of years I've been fortunate acquiring e3. When I open the last 8lb jug, I immediately order more. I may have to wait months for it, but it always (so far) arrives before I run out.