SolaceRO is a low pop, 2 server um, server. One is SolaceRO which I don't play much of all, it's a mid-rate and then there's it's brother, SolaceROAP (Which is the server I play) There's your background into the server, now into the actual rating

Servers: SolaceRO, SolaceROAP
Stability (9/10) : It's pretty stable, I don't lag much, though there are a few lag spikes time from time.
Availability (9/10) : Of the time I've played on SolaceRO (Which is about 2 months), it's only been down once or twice. So there's rarely any time it's down.
Friendliness (7/10) : What's a server without a couple of jerks? Every server has one, even SolaceRO. Aside from the norm, the players there are very friendly, and helpful.
Eventfulness (4/10) : I have to be honest when I say, the eventfulness isn't that great. Though that's changing now, more events and all. It still needs a lot of work.
GM Friendliness (10/10) : When the GMs are on, they're amazingly friendly, always answering questions, and just chatting with the players. I have to give a 10 in this.
GM Availability (4/10) : As of right now SolaceRO IS lacking staff, I'm hoping it'll change very soon though.
GM Helpfulness (10/10) : As I mentioned before, when the GMs are on they are always answering questions that the players throw at them. If they are needed, they go where they are needed, if there is a bug, they will go and fix it. Another 10 for the GMs

Economy (4/10) : Because of the low pop and rate, there is NO player shops at all. In which the zeny just sits there idle in the bank.
Guild Competition (SolaceRO:3 SolaceROAP:8/10) : This is where the servers really differ from one another. SolaceRO seems to be dominated by one single guild (Though this may be changing). SolaceROAP has no WoE yet (But this too, shall come soon) but when it does come, it'll have a healthy competition with quite a few guilds of around the same size.
Class Balance (9/10) : The balance, from what I can see, is pretty good on both servers.
Total = 7/10 for a young, growing server, it's pretty good in my opinion.
And here's the site if you are interested:
http://solacero.net/