It is a poor testimony. Saying a stove got up to 1,100 degrees once and still works means very little in terms of the quality and capabilities of a stove, especially a steel stove. Like I said; You can get most steel stove that hot and not have a problem. Doesn't mean it's a good stove.
That gets me wondering what you would like the dealer to say? Just recite the sales brochure? Because I think it will be impossible for them to run all their stoves through months of continuous operation to see how they perform. Since you have not been there you do not know whether he gave the impression it is ok to get the stove to 1100 or whether he advised against it but still mentioned that I held up to it at least once. I would take it as an evidence that it is not cheap because of inferior materials and shortcuts in manufacturing but would certainly not try to get it so hot on purpose. Especially with a new stove without long-term performance it may be one of the few impressions that you can get and I think still better than none.