I ended up ordering the prochrony dlx with a light kit. The ability to download data was a big factor, and reviews indicated it's not so sensitive to other lights when using the light kit indoors. The old beta chrony wasn't happy unless ALL other lights in the garage were off, which made it hard to write down the readings, load pellets headfirst, that kind of thing. And, feeling flush after selling off some old Crosmans, I also sprung for one of those little Vikka units, like 'mattcohen787' mentioned. If it's reasonably accurate, seemed like it would be a light, easy chrony to use outdoors without having to do any set up. We'll see.
Appreciate all the suggestions and discussion here. Thought I'd post how things turned out. And after playing around a bit with the ProChrono DLX and the little Vikka ($31 at Amazon) unit suggested by Matt Cohen, I'm impressed by both. Really like the functionality of the DLX with bluetooth. And shooting CP's through my Marauder SemiAuto, the Vikka averaged 841 fps for 10 shots, while the DLX averaged 835 fps. And no error messages from either. Just because, I also shot thru the old ShootingChrony and got 841 fps over 7 shots ( the other 3 were errors!). So the Vikka, without any function other than to record shot strings, appears to measure fps pretty reliably, at least indoors.
I did a search here, but the posts are from 10+ years ago, and I don't know how to sort search results by date.---snip---