I'm surprised no one has responded yet, but basically you are going to get two big sides on this, the "if you properly vent your heater, then it is not an issue" side, and the "oh my dear lord why would you ever do that it is your life do what you want side".
As with everything, there are risks to it, and as long as you know enough about the systems to safely mitigate those risks by providing proper combustion air sources and fresh air to replace it, then you will be OK. However, failure to do so can be very bad.
For the record, I plan to do it. But that's still a ways away for me
Just do a search on "catalytic heaters" in the heater section and you'll find some good comparison threads.