We have had our 27-5L for over three years and still love it so I’m a bit biased. The 28-5C is a nice floor plan just not for us. We camp a few times with grandkids so the open living area of ours is a bietter fit.
For the TV questions, in the bedroom, plenty of backing to put a mount to. We installed a 24” TV/DVD for the grandkids and not a problem being secure. The living room is a good height. I raised it about 2” to mount a Bose sound bar below it so the sound bar moves with the TV and the shelf remains free.
For the MorRyde steps, carefully determine if they are the best option for you. The factory still special orders the install of folding steps. Ours came with the folding as it was the only option. I installed a Torklift steps over MorRydes due to the space needed for the MorRydes when deploying them. We store our trailer offsite so would have to pull it forward to access inside which we don’t with the Torklifts. Have also been in tight spots the MorRydes wouldn’t work well. It would be a dealbreaker if the MorRydes were the only option.
I’ve had two fifth wheels with MorRydes Rubber Pinbox which I would say help to reduce some of the bad road spots. Probably not as good as an air pinbox but also no babysitting an air bag.
Best part of Northwood rigs is they make their own frames. I’m not so sure there is a better fram pe in the same price point, but you probably know that.
I’d also suggest to only get a 50 amp power system just in case you ever want a second AC in the bedrooms. 30 amp doesn’t get the prewire
Bottom line, between the two models you mention, the best one is the one that works best for you and your family.