PD03B finally got here nearly 8 weeks after ordering from Easylight. This is my first proper twisty since those dark Maglite Solitaire days and straightaway I liked it. There appear to be a couple of small differences from Vectrex's Brinyte PD03A , but overall it seems to be pretty much the same torch. Small, lightweight, plenty bright enough for a keychain light and fit/finish seem excellent. One handed twist action is easier than I thought it would be, and on/off and mode change work perfectly.
To answer the tail magnet question, there isn't one. At the moment this doesn't matter too much as the torch is on my keychain, so a magnet might even get in the way. I may glue one into the tail recess, but it would need to be of a smaller diameter than the tail ring, or the mini split keyring that I've hooked through the lanyard hole, (and which is linked with a bigger keyring), wouldn't be able to swivel freely. I'll see how things go.
Next point to mention is that this torch is three section. The head unscrews easily, which provides the VERY useful mule mode feature, and there's an O ring where it should be. Nice. But I think they've blundered here, because whilst it takes a nice, safe 7+ full turns to unscrew the head, it only needs 3.5 turns for the middle section to go from light off to coming apart. It would be much more sensible if this was the other way around, i.e. 7 turns to come off at the middle, since this is the bit that will always be slightly loosened to start with (until you turn the torch on, of course). 3.5 turns needed to remove the head would be no problem since you can just keep it screwed down tight all the time. Matter of fact, you have to really, as at first I sometimes found that one handedly turning the light off would accidentally loosen the head at the same time.
As Vectrex notes, the on/off and mode changing twisty action is beautifully smooth with just the right amount of friction resistance, but a few times I've caught the two sections at least a full turn-and-a-half apart. I'd be a lot happier with a bigger safety margin than 3.5 turns.
Another potential weakness is the lanyard hole, which is the only way of attaching a split mini-keyring. You can see from the pic below that the placement of the hole leaves only about 1mm of tail ring to hold the keyring. Ok, I'm worrying before it's happened, but that sliver of aluminium can't hold out forever. I'd gladly add a couple more mm to the length of the body for a stronger fixing point.
What else? Well, tint is perhaps a little on the cool side, but I can only see this when compared alongside the neutral-to-warm tint of my 504b XM-L. It also has maybe a hint of magenta in it, which sounds like a contradiction; cool magenta? 
Well, that's what it looks like. But it's very slight, and like I say, only noticeable in comparison. On it's own it looks nice, at least to my eyes.
Vectrex mentions PWM on low, but the only way I can see it is if I splay my fingers and waggle my hand very quickly in the beam, then it gives a sort of multi-image outline effect. This sounds worse than it is; used normally I can't detect any flickering at all, though tbh I'm beginning to wonder if it's possible that I'm just not susceptible to PWM (or if my eyesight isn't good enough). I have at least a dozen budget light models with low modes and I can't detect the sort of seizure inducing PWM some BLF-ers describe on any of them. Strange. And lucky.
Overall, this is a very nice little flashlight. Couple of minor issues mentioned earlier, but I'm pleased with my purchase so far. Thanks for the heads up, Vectrex. I don't own any 10440 batteries to try, but in view of the PD03B's uncertaint track record in that department, maybe just as well. Though I'd love to see.. 
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