I recently upgraded my old hearth mount setup with an insert. ..
My dealers near me carry BK and a low model SBI (maker of Osburn) at one and Harmon and Hearthstone at another. I had my mind made up on a BK Princess insert, only to find out BK didn't recommend the install with the offset my flue would have to make....
After about a year being set on the BK I started looking again, stopped in one dealer figuring I would be installing another hearth model (hearthstone homestead) and was directed to the Clydesdale insert. It had a bigger firebox (smaller then some may rec with our size homes) and a blower.
I searched here for reviews and experiences and all seem positive so I bit the bullet, I did my own install that way I knew it was put n correct and not just tossed in the fireplace like many have had done.
I still think of the BK sitting on the hearth, but am very happy with the operation of this unit. I can load it up get it settled in and come back 10-12 hours later to a stovetop close to 200°, fan still on (medium speed) and have plenty enough coals for a matchless re-light. The cast iron/soapstone combo heat more evenly than my old steel model with less temperature curves throughout the whole house. My oil boiler only runs to heat my 40 gal water tank
You will have to pick the one that fits YOUR needs and one you won't mind to look at. I would suggest to get the biggest stove you can fit and to insulate the fireplace behind it. Insist on having a block off plate installed and an insulated liner if your flue is on an external wall.
Good luck you will get plenty of feed back from some great people here