A neat little machine, to be sure. Tiny by the standards of the typical rig I work with. I usually hire rigs with 250,000 to 1,000,000 lb load ratings, plunger style mud pumps to 1000 HP, yadda, yadda.
I recall vertical shaft trash pumps from Flygt being very popular for mud transfer. Bentonite slurries to 1.3 SG and 10% solids. Be warned though, thick bentonite slurries seriously affect pump performance - they will still work, but will not be able to deliver at the same rate. I've seen the Flygt trash pumps pass rocks that would not pass the downstream plumbing.