In the single tanks wings, I did not notice much difference between the Pioneer 27 and the Oxycheq 30 and 45 while diving. They felt the same.
The smaller the wing the better the air distribution. You can really feel a few puffs in the Pioneer. The 45 feels a little "slower" on inflation. Air has twice as much room to move around, and you can feel and hear it rumbling as the bubble finds its level.
So, the smaller wings feel nice and tight and the bigger wings feel a bit sloppier.
When surfaced the bigger wings are very nice. With a big steel, can light, steel BP the 27 would float me with just my head and neck out of the water. The 30 got me to my collar bones and the 45 is big enough to get me to my nipple line.
With the 27 in seas over 3 feet or so I would get a lot of water in my face. Definitely not fun in 6 foot seas, but I survived just fine. This is a lot better with the bigger wings.
I also used double and dual wings with singles. The Halcyon 55 double tank wing adds a significant amount of drag in the water. The wing tacos up around the tank and drags on any overhead. It was a real pain.
The Dive Rite 45 dual/single had the same issues. Better, but still pretty crappy.
These big double tank wings feel very, very sloppy. The air rumbles and bubbles and gets stuck more in one part of the wing. You have to wiggle your butt around to get things to settle down. If you lean all the air gargles over to the up side and you have to wiggle it back over when you get done.
Currents catch the big sail that the wing makes and acts like a big old keel. It feels like there is something on your back dragging you around.
Its a pain, but doable.
I use the Oxycheq 45 for all my single tank dives and the Halcyon 55 for all of my double tank dives. The Oxycheq 30 and DiveRite 45 are reserved for loaning.
For what it is worth.
Peter