And here I was leary of those periscope vents, because the vent seems so skinny, and to me that meant it would get build up even faster than the big wide round vents. And again not alot of eperince with this, which is why I came to the forum in the first place.
A periscope-type vent actually has quite a bit more volume than a round one! Having both on hand I'd say 15% to 20% more volume. Secondly, lint doesn't come out as a solid softball, it comes out in small bits.
I prefer the periscope vent because it allows the dryer to be closer to the wall and they're solid. There is nothing wrong with the round vents but I guarantee in a large percentage of homes, the round vent is either loose or semi crushed. Rarely do you have that issue with a periscope type vent.