I wouldnt take my water-logged roots out of water for maintenance for any time longer than 20 minutes...
Somethin just tells me that after they get used to suckin up water 24/7 they dont like being dry for a long time.
I just did my first res change, and although we had to have the plants out of water, they were only out of any kind of water for about... 5 minutes tops, that was today, and about 6 hours ago, they havent shown any signs of stress so far
*fingers crossed*
May I ask what you do for res changes? My first res change, the one I did today, was pretty awkward what with the plants not being in any water for a time.