said 2 months, 2 weeks ago:
It’s quite good. I have it and use it on most of my sites. Great to add nice looking forms in your sidebar and you can also place it wherever you like in your posts via shortcode.
The great feature I like is the fact changes are made globally, so if you amend the optin text or change email provider etc you only make the change to the one form and it will propagate wherever it has been embedded.
It also comes with a good number of different designs.
I’d recommend it.
An alternative to look at is http://www.popupdomination.com/blog/sidebar-2-0-update/
Which happens to be free. I still prefer OptinSkin though.