After being greatly impressed by Zpor's vocal effects in Henge, I ascertained from a live video that he was using a Roland VT-4 Voice Transformer and its forerunner, the VT-3 to transform his voice. I found that the latest model in this line appeared to be the E-4 Voice Tweaker so I picked one up secondhand. Unfortunately I found it rather a phaff to use, so I also got a VT-4 which arrived via the bay of E this morning. My initial impression is that the VT-4 is much more accessible with better I/O options & phantom power on a balanced mic input, although the E-4 does have some cool features not included in the VT-4 — it can be used as an audio interface without drivers, it has a built-in rechargable battery, and the looper & scatter feature are interesting and warrant some experimentation.
Not sure whether I will keep both, but I'll do some recording with them and see how I get on.