I have never been to Czekolada but talking to many of my friends that still live in Lublin they say it is by far the best club in the city.
First, you need to be 21+ to enter. The "legal" age in Poland is 18 ... but as everyone knows, almost noone asks for ID; so what do you get? Clubs and bars packed with 16 and 17 year old girls/guys. Czekolada is different, they check your ID at the door and let only of age people in ... which is good! Im 23 and I dont really like partying with kids.
As for the decor, I heard the club is very nicely outfitted: 2 main rooms, couches and a dancefloor.
Dress Code: Nice jeans and urban sneakers should be ok, but just dont look like a slob!
Komitet is just off the main pedestrain street, in a little alleyway. every Sunday night they have a Karaoke evening, which is great fun. I went there once with my friends, and we had a ball - the only annoying thing was that it was difficult to get your song, as one or two people sang 10-12 times, meaning that your 2 songs kinda got left at the bottom of the pile...
Dress Code: No particular dress code
You must see the old town. It's area between Brama Krakowska and King's Castle. You have to try althogh one pint of beer in each of many pubs.
My favorite is 'Czarcia Lapa' pub in old socrealistic fashion.