I thought it would be fun to write short opinions on technical subjects. Here is the first one.
Latex tubes roll better than butyl ones. The improved rolling resistance is measurable, quantitatively, for example here. The improvement is real, but relatively small - you could achieve comparable rolling resistance reduction by pumping up the tyre more, or through changing tyres. The competitive edge of latex will be of use to the really top flight racing types. The rest of us have much more to gain through training and improving aerodynamics. There is no weight penalty between the two types of tube, because lightweight butyl tubes are available that compare well with latex ones in grams. In qualitative terms, I find latex tubes more comfortable. They have a wonderful "squishy, yet fast" feel to them. In contrast, butyl tubes give a "harder, harsher" ride. Another factor is that latex tubes need to be pumped up more regularly - pretty much every day - as they do not retain air as well as butyl tubes. I've also noted an odd wear issue with latex tubes. See the photo below which shows some kind of plastic deformation on the inside of the tube - I never figured out the cause.
So, if you want fast, comfy tubes with improved rolling resistance and can put up with the extra maintenance hassle, then go for latex. But if you can't be bothered with the extra maintenance (both in terms of time and expense), then stick to butyl.