Looking for the same application for our new build and are leaning toward the Montebello. Was lucky enough to find a model installed locally at a showroom. There is the tricky part, most have the Montebello but not the indoor/outdoor version to actually look at. Its an impressive looking unit and I was suprised at how much heat came off the ceramic face. Not familiar with the other brand but just wanted to toss in the comment. I've tried with little luck to find reviews/info from other gardenwebbers and the internet on indoor/outdoor fireplace models. It seems to be a niche market that not many actually comment on.

The title of your post jumped out at me as we looked the the Lennox Montebello, too, for the indoor/outdoor application in our new home. We ended up ordering the Majestic Marquis which was slightly cheaper and a dealer close to us. Sorry I can't tell you how we like it; it has not arrived nor are we at the point of installing it. I think I am going to love it!

I have had a Majestic gas fireplace for 12 years. I must warn you it seems Majestic goes in and out of business regularly. Therefore parts for units are very expensive, a $12.00 thermocouple is now $54.00 for my unit.