I realize this isn't a super racy bunch. I do race (mainly cyclocross) and don't discriminate based on frame material I own both metal and plastic bikes and love them all.
That being said I found myself in a pinch recently. While waiting for my new Rock Lobster disc cyclocross bike I realized I didn't have a bike for the Lost and Found Gravel Race which was held last weekend outside of Portola, c CA.
Fairly last minute I decided to convert my early 80's Specialized Sequoia commuter to 650B. I bought some clearance Pacenti SL23's and 105 hubs. Built them up 32 3x and put some cheap Col De La Vie tires on. I didn't think I could like that bike more than I already did. Wow. The thing I noticed the most was how it seemed to descend much better with a lower bottom bracket that was achieved the smaller wheel diameter.
Knowing what I know now I'm not sure I would have ridden the disc cyclocross bike had I had it in my possession.
Pics of the bike post race.
Cheers,
Zac