I am 6'2...other than being aware of enter/exit, I have no problems in our 17FD...keep in mind these are small areas and to make the most of your camping adventure, you must spend a big part of your time outdoors...there simply is not enough room inside to just "live" there.
We have made our bed permanent by putting an 8" thick, firm foam mattress there and use the side dinette in the FD for our seatting needs...you only have a narrow ailse between the bed and bathroom.
The bed is only 76" long and while tight will work...we use a king at home and make do(quite well) in the camper...it is a compromise but, consider, you have your entire "house" squeezed into about 84sq feet...
If you can, you really should try and get by a FG rally
to see various sized campers.
The 17' Casita is an excellent compromise of size Vs cost, towability, maintenance and ease of use...a ginormous 5th wheeler it ain't...
We truly love our Casita and while we would look at an Escape
19 R 21, look is about all we would do. You really need to consider spending most waking hours outside to make the best use of your experience, going in for heavy rain, maybe meals and sleeping...we do most of our cooking, eating, dish washing and general "hanging out" in the outdoors, which after all is why we are camping.
...apologies for being long winded............
p.s. when we do go indoors around 10, we sit at the dinette and play cards or dominoes, maybe even watch a DVD or tv(if signal available)...one of the big pluses is being able to access drinks and snacks without getting out of chair.......mj