My opinion is different, having used and owning many 8" drives, including the TM-848s. The 848 has one big flaw--the 24VDC is used only for the drive motor--it's dropped to 12V by a 7812 regulator for everything else. Two failures are very typical--the capacitor on the input to the regulator fails short, with the result that a picofuse on the PCB gets blown--or, the 7812, even with the shunt resistor, is sorely overloaded and sometimes fails.
My preference is for AC-motor drives--absolutely no trouble with them. My day-in, day-out drives are Qumetrack DT/8s and Siemens FDD-200s. Shugart SA-850s are also very nice drives. All are built like battleships. If you're looking for a drive for those IBMs (yes, they're soft-sectored), be careful not to grab a single-sided drive, the most common of which seems to be the Shugart SA-801. A good drive, but with an obvious limitation. Whatever, if you get an AC motor drive, be sure it matches your line power. A 220V 50Hz drive isn't going to work well without substantial changes on a 120V 60Hz circuit.
Japanese 8" drives can be a little strange, particularly ones from NEC, so if you find one, be sure to get a manual for it. Early on, there really wasn't a standard for 8" drive connectors, so a manual is valuable in any case. One notable zinger is the old Calcomp 8" drives with power to the drive being fed through the the same 50-conductor ribbon cable used for signals. Plug it in upside-down for a real surprise. Other older drives, such as PerSci, Innovex, Orbis, etc. have their own peculiarities.
Note that for all of these drives, you'll need a 24V/5V (and possibly -5) power supply. 50-to-34 pin adapters, if you don't want to roll one yourself can be had from John Wilson at DBit.