(keitai-l) Provider selection

I realize this may not be the best location to ask this, but it's hard to
find good information for a gaijin like myself.

I'm going to be in Japan a year or two.  I'm not new to Japan, but this time
I'm going to need a cell phone.  Can anyone tell me what the pros and cons
of going with JPhone versus Au would be?  People are telling me that Au has
generally superior service (less drops, more accessible) but that JPhone has
superior bilingual phones.

Can anyone comment?

Thanks