Remember, this pipe has a realizeable mu of ~2. Up to 3 if you run a lot of current through a CCS. With R_p of ~500R, and 5W of plate dissipation, it should be an excellent choice for a split-load PI. B+ of ~350, and 3k load resistors.

Or a linestage with ~300V B+ and a 5k plate load. 200V across the load, and 80V a-k, with the rest as cathode-ground.

I am going to use them for a low voltage hybrid cascode as in Merlin v2, with the gates between 30 and 50V. Mmmmmhhhh...creat-a-pentode.
cheers,
Douglas