Why would you ever want to go T4 other than for a Panther? Especially when for that price you could just get 2 PIV's, or a PIV and a StuG III or just a smattering of StuG III's and Ostwinds.
This patch hasn't solved the issue of Ostheer T4 being aggressively mediocre for what you pay for. It would be a fairly easy fix just to give the Pwerfer it's old rockets back and make the Sturmpanzer move like the crew isn't drunk and lower the cost of the Panther a tiny bit.
T3 has literally everything you need in it, T4 has overpriced mediocrity.
You're paying bigger price for superior units.
You may call it what you want, but you're getting superior armor there that will beat every single other tank 1v1 short of IS-2. That isn't medicority. Brummbar also performs excellent against infantry right now.
Only pwerfer isn't super amazing, but god forbid single soviet stock unit would perform better then its ost counterpart for the same cost, you already have superior sniper, superior generalist infantry, superior AT gun and superior mortars, can't have everything superior, sorry.
There is no problem holding out to T4 with command tank, especially now that it got a tremendous buff.
Lowering panthers cost would equal lowering its stats.