I voted 4, there are not many company for F2P games that I like. Aeria is one of the few that I like. Seriously I have never got any problems with Aeria before. I am a Latale player and so far very satisfied with Aeria service ^^
What you can do to improve: Well I cant think of anything right now, but in Latale we have got many disconnects (for server maintenance and such, which is late btw) randomly. I think the GM should have notified us 10 mins before the maintenance. Also I think GM's should inform us as much as possible. For example during maintenance time or patch time, many people will be reckless hanging around forum and shoutbox, hoping for at least tiny information.
Tiny things such as "Dont expect update to be soon for at least 2h". Even it may sound depressing, it also will be a relief to the players. Also things like "We just got some hardware problems, so maintenance will take longer than expected". Anything is fine, dont be afraid of disappointing us, even disappointing news are always better than no news at all. It will be alot more depressing just to see "update is over, log on and enjoy" (after 2h of waiting) just to find out NOTHING have been added or fixed. Then on patch note it says something: "NPC name of town X named Shara have been fixed to Sara, I wish you all good luck with gaming!". That is the most depressing ever.
Not like I am saying that Aeria is having these problems, just telling you guys to be aware of these situations. Sorry if I sounded offensive, that wasnt my intention at all.