I do have a few niggles with it - you can set up hierarchies of tags (like for places you can have UK with subcategory London with subcategory British Museum to use an example from my tags). But doing this on the fly as you set tags doesn't always seem to "take" the supercategory doesn't always turn into a supercategory, although it's easy enough to fix by going back to the kphotoalbum settings and sorting it out there. If you have more than one level of nesting tho neither the way to do it in the settings nor the way to do it on the fly visualise this very well - no treeview at all in the place where you set tags on photos, only 2 level deep tree view in the settings dialog. (It does show the whole tree when you're actually navigating your way around the photos with the tags.) And I found that if you click "British Museum" to add that tag to the photo then it also adds tags London and UK (as it should) but doesn't show you this - no wee tick next to the supercategory tags. Again, not an issue coz it does the right thing, but putting both those things together it feels like you need to have your whole tagset in your head the whole time to make sure it's both organised properly and you set the right tags. Or have a flat tagset I suppose, but for Places & People & Events it makes more sense to have hierarchies, I can imagine when I would want to find photos in "Family" for instance and easier to have already grouped them. For keywords it makes less sense, tags in this list are things like "cat" "camel" "pyramid" which I could group into sorts but that would feel more like making a heirarchy for the sake of it.
My other niggle is that setting things up feels a bit disorganised - you do some things in the settings dialog (top level categories, most effective way to do hierarchy organisation), some things in the annotate dialog (renaming tags) and yet other things in the viewer window (making a particular picture of a person be the custom icon for the tag for that person). And it forgets the size I want to view photos at in the viewer window every single time I start the app, defaulting back to 100x100 (and if you just resize the window you stretch that thumbnail so end up with pixelated crap).
Good things, however, are also present. It neither seems to notice nor care that I'm pointing it at a collection of photos on a different computer mounted over nfs in folders it can't write to. I really like the token-setting feature - basically tokens are temporary tags, as you look at a picture in the viewer window you can press a single alphabet key and it sets that token. So I went through a bunch of our egypt photos setting tokens J, M, D, C or S if they had J, me, Derrick, Christine or Steven in them. Then when I was done I went and selected all pics with token "J" and tagged them as "John Patterson" etc. Very quick and simple. And then there's a simple way to remove tokens from all photos. And I've just worked out how to con it into copying me a bunch of the photos somewhere else, for if I was going to edit & upload (it thinks it's exporting, but I'd delete the file it produces for import again).
So, a success, found an app to do the job I want it to do, thanks marble :)
Of course, now I've played with it a bit I think I need to strip most of the tags off the photos I've done and start again, doing things somewhat more systematically ;)