A good tube to use in V1 and V2. Be careful using this tube in the cathode follower position (sometimes noted as V3 in some circuits) due to the high voltage that might be present in this position. Know your circuit; otherwise, play it safe and use something else.
Probably, the best balanced new production valve. Works fine in any position. In V1 presents low noise and microphonic issues and delivers a full, round and silky sound. Clear and defined even under high overdrive. Slightly in the dark side, helps to tame down a bright amp.
In PI positions, can do the job as well as a Sovtek LPS does.
Probably, the best valve for the money.