Well, that went more quickly than I thought it would, though I don't know if I've adequately checked out each of Mr Crispy's points (love that username!) with respect to Collectorz
Photo Collector . However, here goes:
1.
Fast and reposnsive. I'm working with over 10k pictures. I have over 12k pictures in the database that I generated using Photo Collector. I tagged some obscure pics from a few years ago, shut down the program and then searched for part of the tag. The results were returned in about 10 seconds, which I don't consider too bad at all.
2.
Ability to select a folder in the tree view and see all pics in that and its subfolders - not currently. Views are independent of the folder structure in Explorer. However, looking at the users' forum, an Explorer view is in the works. I have and use mp3 Collector which already has the Explorer view implemented and it works really well.
3.
Tagging support for XMP and IPTC. Import and export. Definitely supports IPTC but I can't find anything about XMP from within the program or on the website. I also have no idea where to look for this in my own files, so I can't check it out.
4.
A proper way to organize/filter views based on tags. Yes, this is one of its strongest points.
5.
File monitoring for new folders/pics. Not that I can tell. However, if they get Explorer view up and running (see above) this will be a non-issue as you simply navigate to the new folder and/or file and from the context menu select "add to database". This is how it works in mp3 Collector, anyway. Also, the scanning for photos on your harddrive feature includes a number of options for dealing with a photo that is already in the database including update the database entry (if the photo has changed), ignore it altogether or replace it.
6.
A nice UI with support for multiple zoom levels. The first half is subjective, but I would argue that the answer is yes to both.
Two issues worth noting are that donationcoder still has a 50% discount running on Collectorz.com software and that the licenses are for life - ie come with lifetime upgrades. So far, I am impressed. It's a heck of a lot more responsive and less resource intensive than anything else that I've tried.