I also think version 3 is the fastest. I've loaded 4 and have been using it ever since. I've also tried 5 because a friend was stupid enough to buy it even though he's read all of the negative reviews about 5's render time. The only reason I haven't reverted to 3 is simply because I'm too lazy to go through the process. Yes, I realize it will only take minutes to dump 4 and reload 3. My opinion of 5 is that it is way too slow, slower than anything they've released, no matter what you hear or read.