I'm going to step out on a limb here and say I like liquid better. However, as someone else has pointed out, most liquids aren't true waxes.
Either way, I prefer the liquids for ease of use. Typically a few small drops on the pad are all that's needed and products seem to last forever. I'm perfectly happy dripping a little product on a pad vs. having to find a good way to dig product out of a tin and get it on a DA pad. I go with DA as I've found I can apply the product much thinner and evenly.
I've not notice any longevity penalty in using a liquid. The old carnauba paste I used many years ago (One Grand Blitz) would last about 2~3 months. 845 will easily last me more than six...more than long enough.
After saying all that, I am looking for something different for my black car and going with 915 or a sealant with a product like Natty's or Max Wax will put me right in the past arena anyway.