I'll add my opinion, though I've posted it a couple of times already. For the "significant" improvement of rolling resistance - I've seen 4 watts per tire claimed and more common is 1.5-2 watts per - Latex would be worth the price and hassle BUT ... the faster air leak is a deal killer all by itself. The MAIN thing I want from any tube is "hold air" and Latex tubes don't.
So my verdict is "no", I'll even take the thick heavy cheap tubes over Latex.