I saw a Bronica ETR Action Finder for sale that I think I tried once and it was really heavy. However, I've reconsidered using it as I will be planning to use my Bronica ETRS for more "actiony" work (people moving around, capturing events). Currently I use the non-metered prism and love it. Not only do I get a really nice view of the frame, I'm also able to SEE the microprisms (I have bad eyes so the massive screen is a huge help)! I'm wondering if there is a major advantage to using the Action Finder? Is it okay for critical focusing? Does it dim the image? Thanks!