The flexibility with aiContactSafe is just fantastic, and the Joomfish compatibility is the main reason I went for this in the first place.
I will for sure use this as standard in all websites going forward.
I would however not recommend this for beginners though as the flexibility (read complexity) herein might just prove to be to overwhelming.
I am not using Paidsystem due to the fact that it require users to top up their account on your site before they can spend. I see this as a major showstopper, and believe a simple paypal/creditcard payment extension is the only way forward, but such don't exist today.
I use Adsmanager as a catalog tool for a website, and it looks great. However, when used in that way it would have been good to have a shopping cart extension, but this does as far as I know not exist.
Finally, If you run into trouble with this extension and find your answers in the forum, then fine, but don't assume you will get any help if you post a question as my experience is that support is virtually non existent.
Mind you, I use 1and1 as my hosting partner, and had to configure the php to v5 before I got this working (1and1 use php v4 as standard unless otherwise specified).
This extension has helped me several times as I now can find, compare, and return to previous versions of articles.
This extension is easy to use and I believe it simply is a must for anyone looking to make life easier for themselves when working on a live site.