Hi Fabio,
Sorry I am coming to this thread a bit late!
I use HEE a LOT and still find it one of the best for generating rich layers of natural sounding vocal harmonies in a variety of ways. I also have Nectar 2 which to my ears is poor by comparison and Melodyne, whilst great, is a different beast i.e. pitch correction rather than harmony generation. I know you can create harmonies manually using Melodyne and I have done this but it is a slower process than using HEE.
I wasn't aware of the HEE 4.1 update and I am still on v4.009. Based on your feedback from Antares I will hold off updating for now.
I have used Evo in a variety of ways but the way I prefer in Sonar is on a stereo AUX track by sending the treated solo mono vocal (compressed, eq'd etc) to it. I have created some nice vocal layers by creating multiple AUX tracks with different harmony treatments (low, middle, high register, panning, choir modes etc). In fact one of the limitations of Studio One Pro (my other main DAW) is that it doesn't have AUX tracks. So you have to output vocal tracks to a bus with Evo inserted on it. You then have to output that back to a stereo track to achieve something similar to Sonar's Aux tracks.
Would be interested to hear your experiences of using H Evo. Originally I used the chord mode with different chords set up on each of the buttons manually clicking on each one as the song progressed but eventually worked out how to automate the button changes (it was a bit fiddly though). Now though I find it quicker and easier to use the MIDI input to achieve the required harmonies and record a specific harmony MIDI track or tracks.
ZT