I like full-range drivers, but, I particularly like them as extended range drivers in multi-driver systems. The Jensen/ERPI M-10 field-coil driver with a tweeter, as an example, makes quite an extraordinary system. I also heard a two-way system using the Japanese GIP-4165 field-coil driver (Western Electric clone) and that was killer good too.
As for true full range, single driver systems, the best I've heard is probably the Charney with the Voxativ driver. It delivered the speed and immediacy of single driver systems without sounding harsh, nasal and peaked in the upper midrange and treble range; the primary shortcoming was a lack of high frequency extension. Voxative also makes a very good sounding full range system using its own drivers. A friend utilized a field-coil Feastrix driver in a nice custom system, but, it really needed something to boost the bass response.
While I do like the immediacy and liveliness of the Western Electric/Altec 755 driver, it is WAY too colored and tinny for my taste in a single driver system. Its much rarer cousin, the 756 is a better driver, and it too, still needs a tweeter. The addition of a tweeter, even when the full-range driver is being run full-range (not being attenuated by the crossover), somehow smooths out the response and makes it less harsh and ragged sounding.