We got a Jotul direct vent gas insert put into our prefab fireplace last year. We shopped around a lot before deciding. You might want to look at the Jotul fireplace also. But it might confuse you even more. We were told that the Mendota is "the best." It's also the costliest. We went with the Jotul because it has an excellent reputation and because my wife traveled on business to Norway many times and grew to trust their things. (We also have some Norwegian furniture.)

I do not know about the other brands you mentioned. A few words of general advice based on our experience:

(1) Make sure you have an installer who is experienced, preferably experienced in the item you have selected. I cannot stress this too much. You don't want somebody on a steep learning curve at your expense. That's what happened to us, and our installation is still incomplete after more than 6 months.

(2) Direct vent generates A LOT OF HEAT. It starts slowly, but after a while it feels like a blast furnace. Therefore, it is very important IMHO that you pay extra for the remote thermostat. That will shut the thing down before your bedroom feels like a sauna, and then turn it on again when the thermostat calls for heat.

(3) Make sure you get a system that has true direct vent technology. That will be the most energy efficient, and will protect the quality of your indoor air. This is especially important for units in the bedroom or other sleeping rooms. Unvented units are actually outlawed in some municipalities because they consume indoor oxygen and pose a safety hazard.

(4) Although we are very please with the performance of our Jotul insert, we are disappointed in that their 800 customer service # is really meant primarily for their dealers. So when you call with a question, you get a recorded message directing you to your dealer. I didn't like that, especially after I saw that our installer demonstrated a lack of knowledge about the unit.

Good luck with your decision.

We looked at the Xtrodinair as well. We liked the fact that it looked very much like a traditional fireplace, especially with the firescreen that is an accessory. There was a fair amount of blue flame at the bottom of the logs though and I am not sure if that was just the way that it was installed at the store or if that is standard. Did the one that you saw have this too? The blue flame made it seem much more like gas than a real wood fire to me.

I think that whether the flame is blue or red or a combination can be controlled somewhat, but I'm not sure. I remember reading that in a kitchen stove a blue flame is optimal because it is hottest. But that's not what most people want in a fireplace flame. Ours is pretty red. I think that some conventional gas logs, especially the Eiklor brand, will give you a really dramatic dancing flame, but they don't have the special advantages of a direct vent system. The direct vent flames are somewhat subdued by comparison.

I would go to a dealer that has several direct vent units on display, so you can compare them. And by all means ask some detailed questions about the flame color (and height). A knowledgeable dealer should be able to answer these questions.

Happy hunting.