how about an opinion from a retailer. personally i would never ever buy in channel rainguards for my vehicles.
I am not a retailer, just an end user but from my experience (and personal taste) the in channel type are the only ones I'll buy (and I have had the stick on type in the past).
My first set of Weathertechs are on my Silverado. I've had them on for well over 10 years now with no issues at all.
I put a full set on my 4runner about six months ago. When I first put them on, I did have some sporadic (maybe 25% of the time) issues with the Auto-Up on the drivers side (The window would start to go up and seemingly "hit" the visor and go back down). A little annoying but not a show stopper IMO.
2 months ago I had the front windows tinted and the installer asked me to remove the visors so he could cut out the tint using the outside glass as a template. I did and left them off for a week while the tint "dried". After re-installing them the window has worked perfectly 100% of the time since. My theory is, I did not have them seated correctly the first time and now that they are, they work just as perfectly as my other set.
As far as them "occupying" the same space as the glass, the "blade" of the visor (the part that actually goes into the channel) is very thin and those channels are rubber gaskets with plenty of give/wiggle room. This is really a non-issue IMO.
I say get them. They are very well made, they last, you don't have to stick something to the paint or frame of your door. Can be removed and re-installed if/when needed and in my limited experience, as long as they are installed correctly, they will be trouble free.