Yeah it works no problems so long as the cart has been upgraded to make it run on 1.4 firmware. Lots of the newer carts are pre-flashed, if yours isnt it might need to be upgraded on an original DS before it will work on the DSi or DSi XL.
My current setup is DSi XL with Acekard 2i. I also have iEdge and M3 DS Real for my original DS. Supercard DSTWO is winging its way from Hong Kong.