Click here to go to Keystone's web site for this model and floor plan. I think you miss-typed, it's 41 feet long.
We have a Montana High Country 375FL (Front living room) with a different configuration for the kitchen, bedroom, and bath. We looked at similar models in the "Montana" line and did not like the kitchen arrangement. When the slides are in, too much of the kitchen was not accessible. Like you, the counter space seemed very small, even with the built in shelf between the upstairs and the kitchen.
Question? Is the half bath really necessary, unless you are bringing along more than you and your mate and planning on using the upper living room couches for beds. If just the two of you, you may want to consider the similar model that has the pantry in that space rather than a half bath.
Also, do you really need two sinks? How often do you and your mate, at the same time, share the bathroom together? That's a lot of space your giving up for such a short amount of use.
On the plus side, the upper living on these models is fabulous! Windows all around, and the open feeling between upper level and kitchen is great! No wall also makes the heat and cooling temperatures not so much. Our upper level still runs about 5 degrees hotter than the main floor, Summer and winter. The ceiling fan in the kitchen helps circulate and keeps the temperatures more even. But still, stepping down 3 steps, and you feel a difference in temperature. Sitting about 4 feet higher makes a big difference. I can't imagine how much different it would be if there was a wall and the upper floor was a bedroom.
Another thing to consider is the outside awning. When the front awning is extracted and the dining room table slide is extended, the space under your awning looses a chunk of sitting space outside.
One more thing. If you are bringing alone extra people, other than just the two of you, you no doubt are planning to use the front couches for bed. Yes, the opposing slide couches in the living room can both be opened up and together, end-to-end can actually be slide a little and touch (mine are not anchored down, they can slide. And this makes for one GIGANTIC family bed where about 30 people can sleep (no... not really 30, but 2 adults and a couple of kids, real easy). HOWEVER, no doubt you'll have Thomas Payne furniture and those couches made to a bed look nice, but they are NOT comfortable. At first they appear to be comfortable, but the longer you lay there, the more you feel the folds in the couch, the metal jabbing you in the back, and the head seems to tilt down-hill. (at least mine are). Anyway, it's just something to think about.
For a couples camper, this is a nice floor plan, as long as you are not going into it blind and clueless. After actually using it, especially if have guests or kids, you may find it's not so nice after all.
Another thing, our adult son and his little boy camp with us often. They use the front living room and if the campout is extended, (like longer than a week-end), pulling out those couches to sleep on them every night and then packing up sheets and blankets every morning and turning them back into a couch and stowing away all that bedding is a REAL pain in the carcass. We finally got a blow up Coleman mattress and laid it on the floor. It was more comfortable,
On the other hand, there are a LOT of people who really love this floor plan.
All I can advise is, check it out completely before plopping down $70,000. Have the dealer pull the slides in, set up the front couches-bed, and see what is really accessible. Lay on the bed, sit on the toilet, test out the dining area chairs, and make sure you have enough room sitting at the table for your belly! Because, behind those chairs is a wall, and you cannot slide them back any farther.
One more thing..... consider where the dump valves and the black and grey tanks sewer lines are hooked up at. Are they under a slide? Consider you are at a full hook up site, and climbing under the slide-out ever few days to dump tanks. It's not comfortable ... I know. I did not catch that myself on my current camper either.
One more thing, towing a trailer 2 or 3 feet longer will not be noticeable.
Sorry, if I'm being a downer. I'm just trying to give you some things to consider with this specific model. It's your choice and may work perfect for you. And if it does... WONDERFUL!