Great post.
To add my own personal testimonial that tunnel flying adds a quick learning curve (affordably) to perfectly compliment skydiving like a simulator for flight training... it works for slow learners too!
You don't have to be a natural flyer like J. Russ or fearless like Derek Cox to benefit greatly from what these tubes have to offer skydivers. When I started instructing at SVCO, I had an embarrassingly low number of jumps. (Think 30ish.) After a two year absence from skydiving but a good handful of hours in the tunnel, my recurrency jump was a successful, safe and fun 3-way sit. Every skydive since working for a tunnel has been an incredibly fulfilling learning experience for me.
Since then, I've been traveling to Eloy as often as I can for some great freeflying. Wanting to be a "well-rounded skydiver," I signed up for a couple one-on-one coaching jumps to translate my tunnel flying into the sky. After two jumps, he wanted to give me my money back. If you want to hear the stories of the looks I get after doing a 4-way HD jump and telling them that it was my 50th skydive or the time I chased some belly-flyers and nailed my first hybrid even though I hadn't flown on my belly in the sky for 3+ years, etc... PM me. Ask anyone around here, I'm a sloooow learner and don't have a lot of actual skydiving experience! But I promise if you make a jump with me, I will do my best and not disappoint.
Wind tunnels are not a wonder pill. It requires hard work, dedication and a good attitude to reap all the great benefits they have to offer. So give it a shot and see what it can do for you too!