There's also the question of when you want it. If you want it before September/October, then your only option is the iLiad (and you'd better order very soon given their lead time). Sony isn't expected out before Sept/Oct, and HanLin is ... well I get the impression that nobody's sure when it might launch. (shrug)
iLiad is the more expensive option at ~700 USD or 649 Euros (including VAT).
Sony & HanLin are aimed at ~350 USD.
Sony is aimed primarily at US, no word on whether it'll make to other lands, and HanLin plans to hit US & europe with the V2. Though if you're travelling to China, you can theoretically get the V8 ... but we're not sure where, and it's in chinese.
Personally, I'm waiting at least until the Sony is out, and I can see one of them in person. I've had a first-hand look at the iLiad (thanks to the generousity of a fellow MobileRead-ing iLiad owner who lives near me, and can be bribed into showing his toy off with free coffee). Its screen is really amazing, I was
expecting the screen to be great and I was
still amazed.
However, I think the 6" screen is probably big enough for my purposes, and $350 is certainly a better fit for my wallet than $700 (though still quite steep enough, thank you). For me, it comes down to just wanting to read e-texts. I'll probably go for the least pricey one that does that little thing satisfactorily.
All three will read TXT, PDF and RTF (though iLiad doesn't quite yet -- RTF I mean). Sony doesn't do native HTML/XML, but the others do. If you can convert your texts to one of those formats (easier said than done, I know), you should be in good shape. Since you've already got a good collection of texts, you may want to wait and see who picks up what reading software. Maybe one of them will portal
µBook, who knows? That'd help some.