I have a barn 1/2" full of slabs (and more to come) but it can be a crap-shoot on how bad they'll check. The first thing you MUST do is seal the end ASAP, ie as soon as you cut it the log. Once a tiny check starts, it's nearly impossible to stop it. I've noticed flat sawn slabs tend check less than quarter or rift sawn slabs but they are difficult to keep flat. The number one thing you can do to increase the chances of success is to insure the slabs dry SLOWLY. Don't get impatient or you will end up with kindling. Bottom line is they will most likely warp and check to some degree so you need to plan for it. I typically cut wide slabs 2 1/2" thick if I want 1 3/4"-+ thick finished tops. As brian066 said, the checks can be dealt with in a number of ways and most folks will over look them when they see a table top made from a single slice from a tree.