Jeffrey123, no I haven't.
I tried different power cables and tubes, I cannot send the BAT to the US, or trust someone here in Greece to perform the upgrade, I believe the bass can still be very good and dynamic in absolute terms when Amperex PQ 7308 are fitted in the BAT.
I changed to a SUPRA LoRAD for power cable (which is very affordable) and although is does not have the best bass among other PCs, it still has a fine overall tonality which I like.
To be frank, I forgot about the capacitor upgrade after doing all these..
Upgrades are safer when performed by the manufacturer I believe.
And all these things COST and are endless..
Not to mention the fact that we are never sure about the PERCENTAGE of improvement that will come after paying XXX money for upgrade.
The good thing when you are out of money is that you may settle down a bit and listen to some music without fantasizing and worrying all the time asking yourself "how would it sound if.."
(By the way, if you DO the upgrade, send me some comments please !!! )