What type of server would gain overall players?

[Nobel]

Blizzlike ?

Highrate Blizzlike ?

Or Instant 80/Funservers ?

What type would mostly gain more players?

[Ground Zero]

Depends, it's not always the type it's what you can offer. People won't want to play on a server with many bugs and content not working, they want something new, fresh, original and ofcourse working properly.

[I Hypnotoad I]

Adding on to GZ..
Some people might want a blizz realm, while others want to hit 80 fast an maul eachother with clubs in an arena in some jungle.
The only way to find out what people like the most is to experiment. Or perhaps, combine them all together.

[Aellya]

Generally, getting players is quickest by having it be highrate, easy gains. However, that type of player is often rude/young and will leave as fast as he arrived.
If you want long term players, go blizzlike, but then they'll also be far more demanding (fixes, community etc) and it takes longer to get hold of them(as that type commits to only one server for years on end).
I can imagine an easy gain pvp oriented server functioning for both types of players, however this would by far be the more demanding course of action as pvp'ers dont tolerate any lag, crashes or spellbugs, and you'd have to think up ways to keep them interested through some extra custom course of progression...

Best of luck

[Nobel]

Yes i notice that too, instant 80 players are not so dedicated as our blizz like players are.