The modules are extra bonus, as you can put all sorts of use(less/full) information on your site.
Bottomline is, it's easy to install, and easy to use, and best of all, updated to J1.7!
The only problem I can see is that I had to buy it on faith, it wouldn't display properly on my template, and I couldn't figure out why, reporting a bug to them didn't help, and they insist on not giving help out if you're not registered. So on a leap of faith I registered thinking that they must be able to solve this.
After registration I opened a ticket, which they responded to immediatey, and they solved my problem within two updates to it.
Just too bad that this leap of faith had to be taken, if they had helped me without registration, this would have been an 'excellent' rating.
A bit strange system with hotfix'es with manual copying, but it's managable.
All problems reported was solved quickly, and Slabbi is very respondent, and have created the docs that's needed (just a question of finding them), one drawback though is the lack of it's own forum, it piggybacks on JoomlaPolis.
The support forum can be found on Joomlapolis and it is linked from JED.
The FAQ can be found in the README folder in uddeIM archive as mentioned in the description text above and as mentioned in the sticky in the uddeIM forum.
The throttling works well, and most of my needs are filled even with the freeware version, again a lot better than I've seen elsewhere.