Just brought an Acekard 2i as well (from www.Aria.co.uk) - I don't usually buy online from companies I've never heard of & usually only ones in the UK
I can say it came in a box just like in the photos on the first page, however it had an additional orange sticker on the front with 'DSI Compatible'
- It ALSO came with a rumblepack, not just the card - but had no Instructions or MiniCD with OS/Manual on (like another card I brought many years ago)
Haven't tried it on a DSi yet - it's on order & due to be delivered on official UK release date - but I HAVE had a couple of times when the DS locked up on booting up (the 'nintendoDS' fade-in screen) after I've played around with the Acekard options trying to figure out what does what
I suspect this may be because of the MicroSD card rather than the Acekard, it's a cheap 2Gb one made buy 'Apacer' that I had lying around, & the DSLite has been bashed around a bit - so the contacts may be a little dodgy.
As said earlier in this thread - if it works with the official firmware then I guess it's legit