Useful or not?
I run one, a very old F118 with the short inner, non-UL side panels. This spring I was looking at stoves to replace and the new F118 Black Bear was on the list. In talking to the salesman at one of the largest Jotul dealers on the East Coast he addressed this very issue. 90% of the fractures and failures are customer error / stupidity. They try to shove too much wood or too large a piece in the firebox and beat the daylights out of the secondary burn tubes. This is considered customer abuse and is a non warranty issue, as it should be. It is not a problem that is exclusive to this model, or brand.
The F118 employs Jotul's cigar burn. Before loading the stove the coals that build up in the rear of the stove must be raked forward. If not the refill pieces do not lay flat, but rather form a ramp to the back. Since you're loading an approximate 2 foot long piece it will go though the door but hit the secondary burn shelf / tubes after 1/2 to 2/3 of the piece is in the stove due to the ramp effect. Instead of removing and and loading a smaller piece or just saying the firebox is full, people just keep pushing and wedging the piece in until the secondary burn shelf is damaged or breaks.
Loading a long firebox stove through a relatively small door just takes a little patience and common sense. I love putting up 2 foot wood. It goes faster with fewer pieces to handle and if it fits on the splitter I know it will fit in the stove. This is a YMMV preference, but it's food for thought.
I have been selling firewood for 30 plus years and in that time I have never heard any customer have anything but praise for their Jotul stove, regardless of the model.
Take Care