I'm getting the 15" flipper from Ampeg. Found it on sale for $330. If it farts on me, I'll upgrade the speaker myself.
Though I agree with Mark's assessment earlier, I think this is a good plan (especially if that cab won't be driven as hard as the spec says it can - being a secondary extension cab). Drivers are easy to upgrade and you can easily get $50-100 for the old one.
just out of curiosty,what cab are you playing through granny g?
The Musicman RH115 I mentioned before is my main gigging rig (slightly modified in that I extended the internal reflex horn and swapped the driver out for an EV SP15c, which is the fastest transient responding and brightest 15 I have ever heard, but still has plenty of bottom - the amp is only a 100 watts vs the speaker's handling of 300 so farting out isn't an issue despite the light cone). Alt cabs include the DIY sealed 8x10 with vintage Rola alnico drivers and 2 1x12 transmission lines with a selection of drivers I swap out for various uses (bass, guitar or small PA for solo acoustic gigs).
They can all be seen in here (Musicman on the right, grey grille, one of the 1x12s and the 8x10 on the left):
wait this one's better (don't let the Traynor badge fool you, that's how I found the MM in the pawn shop; didn't know what it was at the time, but the price was very good, and I'm so very glad I bought it... originally it had a crappy Eminence stamped frame, bottom of the line driver in it), I think that's a JBL E120 in the 1x12:
Dave, I really don't understand your problem or your attitude here and am just gonna leave this alone with you. I was trying to be helpful and I think it was somewhat appreciated so I'm just gonna hit it and quit. Keep rolling your eyes if you must but it's just making you look like a grump. I don't know why you are making it personal like this; we're talking about speakers not politics or religion.