Well, here's my opinion since I've used the XL-1S, XL2 and DVX.
Since you live in the UK, even an older XL-1S is a good option. At 25fps, with it's "fake" movie mode progressive scan, it can be just as cinematic as 24p on XL2/DVX. No one can tell the difference between 25fps and 24fps.
Since you wanted some screen grabs I've taken some for you (but this is just stuff I had readily available on my powerbook).
This is all 25fps XL-1S
You can watch the video online as well >
http://www.flaviuman.com/breathing.html
This video is also available online >
http://www.flaviuman.com/darkness.html
This was all done with the standard lens.
Here's a clip from a video I shot on the XL2 (at 24p):
http://www.flaviuman.com/lily_pads.html
I don't have any pictures to add from that.
You may want to just view the videos above. The images attached here will most likely be too dark.
Of these three cameras I prefer the Canons simply due to their size. I rarely hold the cameras in my hand. They fit pretty nicely on the shoulder. I also like the XL2's focus/zoom recall features. I've also used the other lenses from Canon (the manual and the wide) which was helpful for me. On the other hand, the DVX is nice and compact which may make your life easier.
But in terms of quality, what will make your footage really stand out is your understanding of lighting, optics, set design, etc, etc. I see a lot of footage from all three of these cameras that looks like crap.
So, in my opinion, pick whichever one you want. hehe