I recently got an ikea toddler bed--well, its longer than a regular toddler bed. I only got it for staging my home since ds sleeps with us. Sometimes he thinks its fun to play on though
The one I got, which is longer than the one in your link-- the mattress is sort of an eggshell foam mattress and very comfy. I'm not sure if the one you linked would fit a typical crib mattress but I'd venture a guess that it won't but I could be wrong.
The sheets that fit my mattress are sort of a jersey material and very nice.
If you have to buy a new mattress for it anyway I'd recommend going with a longer or extendable one that they sell because it will last her much longer than a typical toddler sized one but still doesn't take up as much space as a twin.
I've had a lot of ikea beds and they seem to be pretty sturdy and hold up well over the years.
This is the one I have:http://www.ikea.com/us/en/catalog/products/S39836495