We have used this one for a client and i am very pleased with our choice. Very easy to use, has the spot-on features needed.
I worried a little about support, but my worries were not confirmed, Nick is very helpful and there is clearly a lot of effort put into the development.
Intuitive interface, smooth installation, nice outcome.
The extension is pretty complex and covers most of our needs, the most useful for us was the payment integration that we could customize to our specific needs (the payment processor is quite specific to our client country).
The look and feel is pretty intuitive, most of our needs were covered out of the box, the rest we could change pretty easy.
Regarding support - we had some forum posts that got pretty quick an answer, there was one issue that got fixed, but the update process was pretty simple.
Overall a good experience