I used to be an advocate but after 7 years of heating and having my unit developed cracks I'm not so sure. I believe I just about broke even as I keep track of the reduction in my heating cost, but there is the investment in time and equipment to get firewood and wear and tear on your body doing that. So I'm no longer sold on the idea. I will see if the company stands behind it with warranty but it was not over fired, we ran the fan meticulously to keep it at the correct temperature watch the temperature on the box. People can say whatever they want but be cautious. These units are not as good many of them as advertised and warranty can become a difficult to impossible issue. I'm in that process now.
I think it would be appropriate to wait for the response of your mfg before complaining more.
Yes there is an issue with the stove and that sucks (literally, air...). However, if they fix the issue for you (in whatever way), you'll be ok. And you don't yet know what they'll do.
Moreover, them "standing behind the warranty" is a bit complicated in your case due to the specific circumstances in which you bought the stove. Warranty is part of the legal contract that is the transfer of ownership of the stove. Legal contracts should be followed to the letter - otherwise those written contracts don't hold up to much.
Rather than bashing the mfg more (tho I'm appreciative that in this particular post the mfg is not named), I'd just wait and see what the response is of the mfg. The ball is in their court. They might help you - even if they may have no legal obligation to do so. I sure hope that's the case.
Finally, if you only look at breaking even based on heating costs, you are missing things. We all buy stuff that makes us feel good. That never breaks even, in dollars. And a stove or insert may keep your pipes from freezing, and keep you (at least somewhat) comfortable when the power is out. That independence is worth something too. It's insurance. The complete "break even" picture is, in my eyes, thus larger than cost of the stove and the savings on oil.
There is a separate thread on this case.
My two cents, trying to put this particular post into context for this thread. Not trying to offend you - I genually hope things will get sorted out to your satisfaction as I agree that your insert cracking at 7 years is not something that should be expected.