Wow, this product has come on leaps and bounds since I last used it about 6 years ago.
I've used Paint Shop Pro since v5 and loved it back then but in more recent years moved to Photoshop Elements 'cause that's just what you do, right? Maybe not.
When I first bought my Digital SLR camera the de-facto software to get was Photoshop Elements. It's just what everyone said to do. There's screeds of books on it too and it's very good, largely because it's an excellent catalog of all your photos. Sadly, no-one mentions Paint Shop Pro when talking about photo editing but maybe people should start to.
So back to PSP X4: wouldn't say it has the same cataloging features as PSE9 but it does allow you to easily drill down through your folders (and all my pictures are organised by year and topic) so it's easy to find pictures. You can create smart tags to easily find pictures too.
The interface: amazing, what a leap forward. As someone else mentioned, I think this actually has more image enhancing features than PSE9 and on the surface seem more accessible. It's very intuitive to use whereas PSE is slightly scary to the beginner.
The tool: as an amateur photographer, I have recently looked into purchasing Photoshop Lightroom which is a really nice product. Having reviewed this and the demo of Lightroom, I no longer see a need for it. This can do everything PSE can and on first impressions, as much as Lightroom. I love the tilt-shift (miniaturisation) effect and vignetting is very easy too (something that requires more effort in PSE9). It's much faster than PSE9 too (with a quad core processor, 1Gb graphics and 12Gb RAM, I can verify this). Loving the HRD module which allows you to take various exposures of the same shot and merge to achieve the best effect as well as the photo blend module.
BTW, this also comes with a Winzip Pro code so all you have to do is download the latest version. And as someone else stated it (PSP X4) refreshingly comes with an actual pick-up and use manual!
Overall: very nice product and really deserves a lot more recognition. I'd like to make the switch from PSE9 and may do so but will, at least, use this to edit pictures. I've got one of Scott Kelby's books on using Photoshop Elements to achieve various effects Photoshop Elements 8 Book for Digital Photographers (Voices That Matter) but not sure how much I'll need it now.