Are there any working professionals who have gone directly from the telecine to a direct to disk option (e.g. Firestore, nNovia, etc)?

The two methods are not comparable. Digibeta is 4:2:2 8 bit storage, but with 10bit external processing. Portable HDD recorders are either DV 4:2:0 25Mb/s of HDV MPEG2 Long GOP (4:2:0) @25Mb/s.

These days you would be better off getting a 10bit still frame stream stored to a portable HDD to maintain the original quality of the film.