4Front E-Piano Module is a useful VSTi plug-in for musicians who are in need of a lightweight, low-CPU DX-style, modern electric piano sound.
User Interface: N/A
Sound: Sounds like an 90s electric piano that would be used either in the theme song for a television sit-com or an R&B love ballade. This is not a vintage-style electric piano; that is what the 4Front Rhode Module is for. Personally, I am not very fond of this sound, regardless of the generating source, and would never use it in a composition other than for comedic purposes. In this particular case, the sound is very static across all velocities, so it isn't as expressive as some hardware counterparts that I have used. As mentioned by someone else, the release time is a bit unusual and cannot be changed.
Features: Obviously, this free version is only a representation of what the professional version would offer, but with no user controls and only one sound, it is difficult to predict what features such a version would have.
Customer Support: The 4Front website seems to be very customer-focused, and George (the lead developer) posts here often. I believe that he has set up a listserv for his users as well.
Value For Money: It is free and might be useful to users looking for a simple VSTi that does not consume much CPU. Personally, I would not use this plug-in because of my general dislike of the modern electric piano sound. Compared to other plug-ins, it does not offer too much (compare to something like UltimateSoundBank Plugsound Free, which has several instruments in a single plug-in).
Stability: Excellent, but with no controls, I would expect it to be fairly solid.
Overall, 4Front E-Piano Module is a nice addition to the free VSTi community that some might really appreciate.