I think to preserve the coins,slabs are the best option. If you buy a coin that is beautifully toned,the last thing you want is for that to disappear.I have also bounced a few slabs on the floor,and would prefer to crack plastic,than flatten metal.As long you are happy with the coin,their grade won't matter so much,and when you sell break it out. CGS also let you look at past invoices,so heaven forbid anything where to happen to your collection,it's a backup-"ins purposes". I did have a few NGC that were wrongly slabbed which I cracked and had re-attributed.