When using a tx102 the output impedance is typically much lower than a traditional resistor based passive - this is the main benifit of a TVC.
There are 2 parts to the answer though - gain and sound.
1- Gain. If you normally run up at the top range of the passive now then you'll likely need the +6db option . If you never turn past 2:00 or 3:00 or so on the dial then it is likely you really don't need the gain. If you run direct (no buffer) is the top level loud enough for any listening you would do?
2- Sound. I like the tx102 direct but a nice buffer stage can do some cool stuff so if the SCE unit happens to do something you and your system like then you may choose to leave it in. This is imposible to guess ahead of time but if you have it then I'd say keep it around and try it.