Hey! Tell 'bout these sites PLZ !!!!!

Hi! I'm, like many others, constantly being offered fairly unknown, yet highly-regarded trackers, but don't have any info about them....Can anyone, especially those registered to the respected sites, reveal the following information:

1. URL address ???
2. Number of registered members ??
3. 0-day? (SCENE) or specialized content?
4. Invite system ???
5. English ?? ...... if not, what's the primary language ??
6. brief description (wait times ??... ratio friendly ?? .... atmosphere of community/forums, etc.)

rautaportti
elitsällskapet
Rabbit ???
revolt uk ???
czone ???

BTW, I'm offering WildBytes and/or Sharereactor.RO; Are any of the unknown trackers worth swapping with the ones I have ?