I got a friend that had a .204. It was fun to shoot, no doubt. Very fast, very flat, VERY, VERY accurate!! A 5 shot group at 100yrds usually ended up being one ragged hole. It whatever you are shooting is big enough to see under 300yrds, you can pretty much hit it. With that said he didn't keep it very long. Couldn't really find a "purpose" for it. It was great at punching paper and blowing up drink bottles, but that was about it. I think that if we had groundhogs or something of that nature it would be something that I would have to have. I came to the conclusion that it has a very specific purpose. While I think it excels at that purpose, anything outside of that purpose can be done better with something else.
We never reloaded for it at all. Just shot the factory Hornady 40gr V-Max's. Most people say it is a very finicky caliber to load for. A lot of other people said that no matter what they did, they couldn't match the accuracy/speed of the factory Hornady's. That is why we never tried it.
Personal opinion is its a great caliber.....if you have a use for it. But just remember that its uses are limited in my mind. Other people may disagree.