And here is the Audioholics review of the HDI-3800. I auditioned the HDI-3600 4 years ago or there abouts and really liked them. I would have bought a pair but it was not a big enough upgrade from my current speakers. I feel comfortable recommending them though. A little less bass output than the 3800 due to smaller drivers but a good subwoofer can make up for that. Both the DefTech and JBL received favourable reviews so it would be ideal if you could find a dealer to audition them first hand.
The JBLs go on sale on occasion so check the JBL website and Crutchfield. Sometimes you can find big discounts on JBL speakers and they become a good bargain.
EDIT: Just checked Crutchfield and the 3600 is discounted to $1150 each (regularly $2300). Demand D17 is no longer available there but I see them on Amazon for under $1000 each.
The JBL HDI-3800 84lb beast of a floorstanding speaker features triple 8" bass drivers and an advanced compression driver and waveguide. We review it to determine if it lives up to the JBL heritage.
www.audioholics.com