There is a severe deficiency with this technique. The drive signal for V1 is increased in amplitude by the action of positive feedback. The drive signal for V2 is constrained to equal IN1 because tube V3 acts as a cathode follower at this junction. Feedback signal FB is applied to the entire phase splitter stage. Just as FB provides positive feedback to V1's drive signal, it applies negative feedback to the drive signal for V2.
Positive feedback increases voltage gain and negative feedback reduces it.
Forward voltage gain is therefore consumed at the cathode of V3. The drive signals through the system have unequal forward voltage gains. The signal amplitudes are correct, but the gains are not. The gain unbalance causes a DC offset in the output stage that is proportional to output level. The unbalance is responsible for the weak and feeble bass that these types of amplifiers produce in dynamic speakers even though measurements are quite good.