I got some as part of a little test-package from Rollei when they asked some of us to try the IR prototype.
R3 has a very nice base.
Unfortunately, that is all I care for, of the film's characteristics.
Rollei R3 with red filter:
Both are 4x5, developed in acu-1.
If you have applications that can exploit the clear, thick base and/or the wide ISO tunability in different developers, it may be worth considering. Otherwise, I consider it to be a characterless film unless perhaps it is red filtered.
P.S. Perhaps it would be more interesting if developed for positives.