Yeah I have tried it too. I didn't switch to coir without trying vermiculite. I found it way too soft (and too expensive).
I think my first seedlings last year were just coles potting mix and vermiculite, and most plants died because of the constant spring rain I had. They were outside under a lazerlight poly sheeting roofed pergola, but the gutters suck in this house and overflowed right on the chillies, plus the laserlight poly roof sheeting is full of holes (due to the hailstorm in 2009 here, no one was living here at the time, the house is ready for bulldozing so of course it's not going to be fixed ever), so no where out the backyard to keep plants out of the rain.
Anyway, I wasn't too impressed with vermiculite, but I didn't use much due to the cost of it, I suspect you need to use a fair amount of it. Not economical, so looking at other options. That's what led me to perlite and coir, but it didn't work out in my buckets for mature plants very well. But it was at that time (sept 2011) I had a seedling out in the rain with 50% coir that was doing well, and grew much larger than the rest (the rest were yellowing/dying severely and stunted).
And as you know this year I am just starting them in autumn instead, so they get a head start in root development and can handle the wet conditions better.
But I'm still looking at the perfect draining budget mix and containers for potted plants (though hopefully I can just put everything in the ground and not worry about all this in the future).
BTW first billy Biker popped after only 4 days, thanks!