@potroast
Well, my impression is that the commercial version, 4.5, ain't solid as a rock running emulated on my OS4-pre install. I'm not really sure where to point the blame though, so for the time being I won't point any blame at all. It's at the very least most usable, and I'm sure IFX/OS4 will get along much better in the future.
And there is the old saying "save often, save early." ;-)
To answer your "job critical way" query, well, if it's a critical job I'm doing, I feel more comfortable booting into linux instead and having a go with the Gimp. First of all, I'm currently more comfortable with the interface (for some reason, I just have to bring that up on every Amiga portal I run across :-P), and second, there are a few things where IFX just isn't up to date, when compared to the big players.
I might be prone to save my work a bit more often as well if I was to do something very time consuming in IFX, but then, I'd do that with the GIMP (which just drops dead on occasion) and Photoshop Elements (which I use at work, running on a less-than-satisfactory Windows system) as well.
But all things considered, for the everyday sort of tasks it's very convenient. It gets the job done, it's available from within my favourite OS and it's got more features than I'll ever need for the simpler kinds of tasks.
Now, if there'll ever be an ImageFX 5 that's OS4 native, has a few more features and comes off as a bit more stable on my OS4 install, one of the few reasons for keeping my linux setup will diminish greatly.
Actually, for now, I think OS4 native would come a long way to satisfy my needs.
Besides, the announcement does refer to a free download. I don't see any reason why anyone shouldn't download it and try it for themselves, it's definitely worth a go! (Apparently, there's currently an issue with the installer script replacing a few items in the Sys:Classes, though, but that should hopefully be resolved anytime soon.)