Hey Kevin,
Haven't tried the Arista Premium 100. Still getting through the last few rolls of my APX 100 in Rodinal. That's my model for a 100 speed film, although back when dinosaurs ruled the earth I used Plus X. Unless they bring back APX 100, I will need find something new to the extent I have occasion to use ISO 100. With fast lenses in daylight, I kinda like the range of apertures I can use with ISO 100. But mostly I use Tri X but hope the Arista Premium 400 works out 'cuz the price is right.
I had a chance to check out various photography exhibits around town during Open Studios. Lots of interesting work to see. It's instructive to see what people are doing in terms of finding out how out of touch and trailing-edge I am. Inspiring and daunting at the same time. Although in the minority, there were a some people using film and wet darkrooms (including toy camera users and keepers of the flame for legacy and archaic processes). 20th century documentary style photography is pretty thin on the ground, and photography as mere hobby is declasse (peace, George Eastman). There's a cultural chasm between people who have gone to art school and/or think of themselves as fine artists, and people who just have cameras and rejoice in making photos, innocent of aesthetic aspirations. In the gallery-centric world, the concept of the print as art object is alive and well. I'm trying to locate myself somewhere in the mix, and thinking about the differences -- a good exercise.
Maybe it would be good to restore the idea of "hobby" to its rightful place as worthwhile pursuit.
There's still two or three more weekends of Open Studies in SF, with photography throughout. Check it out, plan a route on foot or allow for traffic and parking hassle.
P.