My first question is: should Synthesizer V (i.e. Gen 1) and Synthesizer V Studio be in the same entry or split into separate entries? I've used the two side-by-side and their function differs on a fundamental level, so much so that it is doubtful they are technically the "same" synthesizer (the synthesizer I would compare 1.0 to based on similarity would actually be Vocaloid2 rather than Synthesizer V Studio). People get the two mixed up often enough -- e.g. calling Studio Basic "a trial" (something mentioned a total of zero places on Dreamtonics' website far as I could see, so I'm inclined to think it's not the case), getting it mixed up with the Synth V 1.0 trial, which is just that -- that a distinction might be helpful. Perhaps they could be separate sub-entries under the same heading?
My second question is: what category should Alter/Ego be under? My instinct is to put it under the third category, but it has aspects to it that could place it almost anywhere. It doesn't have a piano roll of its own (in order to use one for it you need to use Alter/Ego as a VST plugin in a separate DAW), with it instead operating based on inputting the lyrics into a designated area and adjusting the parameters of the voice. Without using a separate DAW, it operates in realtime with a MIDI keyboard. Plus, its function is both singing and talking, the latter of which can be used for text-to-speech. Using the default voice, Bones, as an example, he has three voicebanks: English singing, Japanese singing, and English talking.