Talking to Brian about them they do appear to be pretty good but I believe you still have to position them where the animal cant get at them or guard them from the surface. I think you are right about the lifespan and if you hurry I would talk to Brian by phone about them, he does answer your questions honestly and won't BS you. Also they are the Feb special on herpshop at the moment so good savings to be made especially if your thinking of 6 of 'em. If you do go with them keep us informed mate as I too fancy using them in my next enclosure
