Wow, I really appreciate all this feedback. It is an immense help, since I have zero experience with the new emulsions. I've been kinda busy with other stuff, so I haven't had the chance yet to act on your advice. Gotta make up for that, though -- I'll order some this week. Do y'all have a preferred seller? Freestyle? B&H? Adorama? Dwaynes? An eBay seller maybe?
About the Astia, since it seems to have somewhat lower of a contrast and extremely fine grain, I'm thinking that it might be an ideal film to use if I'm planning to dupe the slides later. I've noticed -- and not just now using a digital duplicator, but back in the days when I'd dupe slides using film -- that the contrast increases with a dupe unless one used special duplicating film or prefogged their Kodachrome 25. As a result, the shadows tend to block up, and some detail is lost in areas bordering between midrange and shadow. Seems to me that Astia might be a viable option for this.