have one. love it. i've switched a LOT of speakers out of it. currently i have a CL80 from my tourmaster combo in it (on the bottom), and a celestion english V30. it's a REALLY good mix.
i tried a t75 with the 30, and it's really good too. to
i also had some eminence (OEM for crate out of a combo a snagged on the side of the road in a garbage pile) that sounded fuckin fantastic too, really dark and thumpy, but not loose. i got the code ( 67-93310481 G1) and emailed eminence and the response back:
"12972 was a custom designed OEM speaker that we manufactured to one of our customer's specifications. It is an 8 ohm speaker with a 1.75" voice coil and a 30 oz ceramic magnet. We do not rate OEM designs (that is left up to the customer to test and rate their cabinet or amp), but a conservative thermal power rating based on the voice coil diameter would be about 50 watts. Here are the T/S parameters:
05-RE OHMS 6.80 13-FS HZ 64.80
06-LE MH .57 14-MMS GMS 24.35
07-QM 15.64 15-CMS mm/N .2478
08-QE .620 16-RMS NS/M .6339
09-QT .600 17-VAS LTRS 93.90
10-XMAX MM .05- 18-SD SCM 519.45
11-BL TM 10.39 19-EBP 103.8
12-EFF % 3.95 20-SPL dB 98.0"
(i only posted that just now so someone searching that speaker code could find it through google

)
anyways, two t75s in that cab work great too, but i like mixing speakers in there..
ANYTHING but g12m70 (mine came with those). they're dead DEAD DEAD sounding in that configuration. maybe if they were rear loaded, theyd sound better, as that cab is front loaded.
personally, i'd say go for it!!! you can sell the g12m70s on ebay for 100 for the pair if you plan on putting something else in it. i THINK i paid 250 for mine also.
the speakers are also hard wired for parallel which offers some diversity too.