Visited this venue for a Beirut concert. It really is, as good as it get's. It is a really beautiful venue. We were right in front of the stage. There were no crash barriers, so that we were really close to the artists. You can find everything you need directly in the venue. A big bar, clean toilets, lockers for your personal stuff and a smoking area in the first floor. Paradiso has three floors, in the upper two there are seats. In our case we were free to take place wherever we wanted to. It was not divided in categories, like it is almost everywhere in Germany these days.
The sound and was great. The PA and the lighting equipment in this venue is state of the art.
To sum it up: I highly recommend a visit when a band you like, is playing. We were really early there (20 mins before doors), why we had no problems with long queues. You have to buy a "membership" (for one month) for 3,50€ before you get in.
I hope I will soon have an opportunity to visit Amsterdam and the Paradiso again...