[mgmueller]

Briefly, after 1 hour with BeBook Neo:

iRex 800:
Pros:
Flipbar: I usually hold my readers with one hand. Holding iRex 800 with your left and using the flipbar is perfect. (They should incorporate 180° rotation though for the left-handed users).
PDB support: Very well thought out, you can enter more than one name/credit card combination. Finally I can use my old books from the Palm Pilot era.

Cons:
Stylus: You can't insert the stylus in the reader. It can be put in the cover or sleeve but that's not the same. I don't like the stylus' weight (too light), but that's probably WACOM specific.
Cover: I don't like the build quality of the iRex cover I've bought in addition.
No zoom (yet?): I was quite surprised, as iRex iLiad did have this phantastic zoom capability more than 2 years ago already. I really hope (and I'm pretty sure, given the strong reactions in the market) that they'll incorporate it asap.
No WiFi: I don't understand, why some manufacturers integrate 3G, but not WiFi (at least as an optional add-on). Surfing and shopping all would be the same functionality and would cover additional markets.

BeBook Neo:
Pros:
WiFi: To me, way more important than 3G.
SD card: Easy to exchange, standard SD card.
Touchscreen plus jogdial: Obviously I prefer the touchscreen. But even without stylus you have the same functionality as for example with Sony 300.
Mobipocket support: Great, I really missed that.
PDB support: Haven't tried it yet, but it's in the manual.
Zoom: It's got the "intelligent" zoom we know from iRex iLiad (marking any area via stylus and exploding to full screen). For the moment, that's missing on iRex 800.

Cons:
Metadata: So far, it only does show the filenames, not the metadata. I don't like that at all.
WiFi data: It doesn't remember my standard network, so I can't login automatically.

In direct comparison, I slightly prefer iRex 800's design. I'm not into BeBook Neo's round edges. Without taking BeBook Neo's WiFi into consideration, iRex 800 probably would be slightly ahead. But including the price into the comparison, the picture changes:: iRex 800 in Europe simply is way too expensive:
iRex 800 = € 499
Sony 900 = $ 399
BeBook Neo = € 299

EDIT: After "testing" BeBook Neo for some days, iRex 800 doesn't stand a chance. iRex 800 only wins in design. (And in that area, Sony 900 still beats them all.) But BeBook Neo by far wins in features and price. BeBook Neo already has all the features I'd hoped for on iRex 800.