I played there so I'll share some experience.
Balance.. hm I can tell it was more or less well balanced before wipe so probably will be now too, because of enchant success rate that was 58%(not sure 100%), blessed 70% and blesseds were very rare so only few players had weapons that exceeded +5/+6 after first two weeks, well there were few strange exceptions.
Things I've noticed are: unusually high lethal rate from dagger classes(well not high as 50% lol, but if you were a slow class, dagger could hit you few times then run recover CP/HP and come again and again untill lethal lands), also 90% of mages were necro's/sph/s due to unusually high damage from CDL(maybe it is supposed to be like that but as player that changed alot of servers, I've never seen so many necromancers that start pvp with CDL and not using other magic untill they lose hp, no they just start with CDL because it was OP, atleast before I crafted TTS and got full resists), so everyone that will play there for first time, expect to be 2-3 shoted from PK-ers with CDL's before you can do any action to return.
I remmember someone who had like +12 DBow after about 2 weeks of starting and that was extreemly strange(because statistical rate for +12 were less than 2%, on every 50-100 weapons you would be able to see that kind of ehcnanted one), I've thought it was some kind of cheat and it probably was, so I hope if there was really some kind of exploit that it is fixed now.
Server died after first olympiad period, and many servers do after same event, because first some "factor" clans leave because of fail to get 10 heroes and then like always some highschool kiddos start spaming on shout and people get tired of reading all that bullcrap and then you see someone write about server l2XYZ, hard farmers say go fuck yourself, other players that don't have any S grade ask, when it start and etc., GM is not online to chatban that player and thats basically how you lose population.
Also there was flaw in vote reward system so I've exploited that with ~100 accounts that were made only for vote coins farm, and I would like that same thing won't be present again(because I don't have my uber PC by my side to exploit it)
If someone would ask me to rate the server first week before wipe with grade 1 to 10 I would say 8.5 to 9.
Not bad server at all, mostly because there were no OP donations except for augments, but oh well..