I have the PE Summit insert.
Just had some warranty repairs made, that were covered by the manufacturer with not much hassle.
As far as the EBT, I found mine had the flapper dislodged and was never operational, and fixed that problem. In theory it seems like a good idea, but haven't had a chance to burn enough since repairing, to determine if it is practical yet.
Either stove is going to be a well made, quality stove. Both seem to have a good following of owners here. If ya have a better half that is a big part of the decision making, you may want to show the other half photos of both stoves. The BK is ugly as sin, while the T6 is beautiful. If looks do not matter, than make your decision based on your research and which appeals to you more. You can't go wrong with either one.
I have to assume the EBT does something, otherwise why bother with it. The company could claim just as long burn times with of without. I will say so far, it seems like my fires are much more manageable since I hooked the flapper up on the EBT, since its not getting the added air all the time as it was when the flapper was out of place. I have had some good size loads in it, but not filled to the gills yet. Still too warm here, which is unseasonable in these parts I think.
One thing I would like to point out.
The nominal difference between the T6 & the BKP fire box size is just that, nominal. I highly doubt you'll notice a difference there either way.
While the BK can get supposed longer burn times, this is at low setting. At low your looking at somewhere in the 8,000 to 9,000 BTU range.
Now, a load of wood in any stove can out put a certain amount of BTU's and the BK, PE or any other stove cannot magically create more BTU's from a load of wood.
So yes you can get a 14-16 hr "low" burn in the BK at the low BTU's, but those long burn times do not necessarily translate into heating an entire home or area on the colder nights. So you'll have to turn the BTU output up, for higher BTU's, and this will not give as long burn times as the low setting would. I am no knocking the BK, it seems like an awesome stove. But whether its EBT or a thermostatically controlled cat, btu's is btu's and there is no magic device that can create more btu's out of a load of wood. I know here when its windy as hell and it is below 20 or near zero etc, 8,000 btus is not going to heat this place.
Now a cat burning more of the volatiles, makes sense, but for how long, once the volatiles burn off and its in the next stage, how much is the cat really producing? Similar deal for a secondary combustion set up. Ya get a light show and more burned gasses, but once those volatiles burn down, your going on what is left of the load. If one set up was so much better than the other, everyone would be buying a majority of the one over the other.
Bottom line, make a list of things you have to have in a stove, and a list of things you would like to have. The stove that has most of those two lists, is the stove for you. Last thing you want to do, is regret your decision, after its installed. Good luck.