Did my research about "Revo-classic" when the servers initially started, I pretty much concluded that it's a way for the GMs to rack up more money.
Some examples:
(1) Low Heal of Priests = More pots being bought
(2) 250m+ base experience needed to reach level 99 = More field manuals and insurance to be bought. Just imagine when transcendent classes will be released, how much experience does people need to grind? 250m+ base experience is pretty high especially when you have limited maps to level up.
(3) Hidden lowered drop rate = More bubble gums to be used. Usually, people don't use bubble gums when just leveling. In "Revo-classics" they use it along Field manuals because the drop rate of some servers seems to be lowered. Example: ROPH & ThaiRO
Progession server is nice but you don't need to have renewal mechanics to be a progression server.
With this "Revo-classic" setting, Hunter trapper builds, bowling bash knights, Holy cross 2 hand spear Crusader are pretty OP. Leaving the other classes as s***.
I concluded that playing this "Revo-classic" setting would be s*** but I am amazed on how many players are playing in official servers.
I found my self playing a classic+renewal mix (Revo classic) with transcendent class on a private server and I enjoyed it. I'm pretty sure it's not the game setting that made me enjoy, it's basically Ragnarok. Best MMORPG ever.
Anyway, if you're looking for a revo classic private server, I only know of 1. It's
http://angel-ro.id/ That's the server I played but I quit because I have no time to play.
If someone is planning to make a "Revo-classic" private server. Here are my suggestions for the server which I think would help you out:
(1) Quest boards, like NovaRO
(2) Classic Respawns but some monster spawn tweaks like Anubis in Sphinx 4
(3) English Speaking server
(4) @whereis @whodrops commands (Important as a monster & item database)