I think Stephan makes a very valid point. There an increasing number of phpDoc aware IDE's which actually make it very convinient to use parameters instead of arrays.
The days .phps, cvsweb or chora does that - I'll stop going on about it ;)
As we dont have to specify type for PHP variables - these editors are doing best guesses - it is feasible with functions or static methods, but it involves a bit of luck when it comes to an editor hinting at php methods..
The way you are suggesting to use arrays seems to be like a poor man's parameter hinting.
The only valid reason I see for array using is to:
1) be able to easily pass a number of parameters which get generated by another method
2) to emulate named parameters
3) extendable (future proof)
4) readabilty - Without having to require a specific editor.
We are writing code that is designed to be re-used as easily as possible by many people, it shouldnt be designing with the presumtion that you need a super-ide to use it..
I had a look through my emense libray of really old books ;) - an interesting section of 'Writing Solid Code' comes out as "Make the code intelligible at the point of call" - Not much could be found easily on the web discussing this..
Regards
Alan