I went with frameless in a 2017 21. So far I have had a separation between the glass in the bathroom window (which I fixed by epoxying them back together - I don't care if they fog since it is the bathroom), and a failure of the opening mechanism in the kitchen window. The thin metal pieces between the rollers in the window track & the arms from the opening knob bent, making it difficult to open & close the window.
Eventually, the roller in one side of the track popped out - very difficult to get it back in place & it is deformed enough that it doesn't stay in the track. After that the track separated from the glass, I epoxied the track back to the window and open & close it as little as possible, although it is the window I usually open most often. I expect to replace the window when I return to my home base in April.
Even with those problems, I prefer the frameless windows. I has the framed windows in my 2011 17B, and returned to a wet bed more than once. Being able to leave the windows open when away from the trailer is important to me.
On the other hand, if I was to purchase a new trailer, I would not want the power awning. The manual was not a choice in 2017, and I find that even though the electric awning is easier to deploy & retract, I don't use it as often as the manual in my 17B. Without the ability to tilt the awning & tie it down, the electric is not as useful to my style of camping.
With the manual awning, I would want the windows under the arms to be sliding; the rest frameless.
When I first went to respond I didn't notice that you were from North Van. My response was going to be - if you lived in BC (Vancouver Island for us) - blowing and water are pretty much a given. We had sliders on our Bigfoot and, never again. All it took was one good blow/rain and the inside dinette was sodden. Tried to get it completely dry but, never was 100% and when we sold it, the ply under the dinette needed to be replaced. 
Wish I had the vertical slider that my 19 had.
