I almost always prefer the quote-less versions. You do have to understand the quoting rules to read them, but I still prefer them. Quoting everything explicitly can make code look really busy, particularly when there are a lot of key-value-pairs. It makes for a lot of clutter. Using the fat comma makes things much calmer.
Also, I use a syntax highlighting editor, which I consider to have been quite beneficial to my coding style in general. In this case, the highlighting reminds me that the bits I'm looking at are actually strings. It also encourages me to disambiguate function calls explicitly, for my own benefit, because the highlighting needs the cues to pick up the difference.
Makeshifts last the longest.
