Chunk performance : Air or Stone ?!

Hi,
we build on a very big place (only over earth) and i think about to change some stuff under the earth.
what gives a better performance ?
to delete all blocks and having air or
to fill everything with simple stone ?
i mean one of these must be better that spawner, dungeons, floating water, lava and obsidian...
nolag and orebfuscator are online, maybe it does not matter, idk.

any ideas ?

 

Air. OreObfuscator cant obfuscate air.

 

Having a ton of blocks to render causes some lag on the client. Also Me4502 is right about Orebfuscator. I deleted that plugin because too me, performance > rare x-rayers. 95% of X-rayers are blatantly obvious and easy to catch. The other 5% aren't too big of a deal because they will eventually fault up somewhere else (grief, cheating some other way).

 

i think the same , but i was not sure

thx