Found a very nice used unit with fresh firebrick etc. I understand this is a smaller non-current unit. I am currently using a Vogelzang Defender . Outside of the short burn time it kept my house plenty warm (HOT!). Would I be making a significant performance upgrade (burn time, etc.) with the Lopi? It sure looks nice. I'd prefer some feedback from Sheffield model users if possible but like always I am glad to read all opinions! Thanks for any insight.