I know both of those companies produce a great unit. Either one will be a good choice. I've had a CB 6048 for about 4 years now with no problems. My brother has an earlier version of the same stove for about 12 years now. Also no problems. (he burns garbage in it, boils it over about 3 times a year cuz he leaves the door open and forgets, and has only put the additive in it once.)
I know that CB doesn't use a fan and Heatmore might. Alot of people like the fan cuz it gets up to temp faster and shuts the damper faster. Makes sence to me. Some people say the fan blows alot of heat up the chimney instead of keeping it in the stove... also makes sence...
I can't give you any advice on Heatmore since I don't have one, any I'd bet you wont find someone who has had both stoves, and even if you do, that person probably hasn't used them each long enough to form a valid opinion on them since most people keep them for at least 10 years or so. And if they have used both stoves for 10 years or so, the first stove may have changed in construction so much in the past 10 years, that the new model is completely different by now. Good luck in your search and maybe someone else can chime in.