All of my tanks, from 55g to 90g have been on carpet for over 14 years. The only drawback is if the thing springs a leak. I had a HOB skimmer (Coralife), that would leak or dump water regularly, my sump leaked once, and I had a 55g break...and clean up is a pain. I keep sham wow's handy, nothing picks up water like that material, for the bad leaks...a shop vac, then the sham wow's to really get the last bit of water up.
Purchase them, and may you never need them.