I will always recommend the Eminence Delta Pro 12a. It's cheaper, higher wattage rating, and a bass speaker BUT has no coloration of sound like most bass speakers do.
Unless you really really dig the sound of speaker break up, I'd probably go for something with a little higher wattage. What is it that you are running into these speakers?
I do like speaker break up, but at a certain point speaker breakup isn't necessary when it's backed with, fuzz pedal & overdriving amp Orange OD120 (but if I get a quad of 30watt speakers I"ll pull two tubes and run it at half wattage) I should just stay away from low wattage speakers.. (but they're only 550$ for the quad.. damn good price)