Actually, yes I have!
This is a good choice, as is any high efficiency speaker. The higher the rating the better, at least 100. I would think you would get a lot more bite and clarity out of it if you go for the ones that have lighterweight magnets.
http://www.eminence.com/guitar.asp?speaker_size=12
If I were doing this project, that Tonker Lite would be especially attractive. Too bad they dont make a Swamp Thang Lite!
I dont know if Celestion has any decent speakers with a rating of 100 or better. Maybe the Hot 100? That amp also sounds really good thru a low power Weber Blue Dog.
Of course, I should qualify this by saying I did these experiments AFTER I had already done every mod in the book (except the tone stack) to my VJ head. The OT mod being the most important one.....