[TECK]

In my opinion, bandwidth will always be cheaper than CPU time or disk.
Very good point, mute.

I'd hope that any site that is doing enough traffic to justify a memcache setup would most likely have an unmetered private network between their servers.
Another excellent reflection.

So what do we do. Do we put emphasis on the memcached or XCache? In other words, more queries and less PHP files to be cached?
Personally, I never liked executing queries. Instead, I cache the query data with XCache... avoiding possible table locks. I have this theory: the less queries you run the easier it is for the MySQL server.

Recently, I had an interesting talk with one of the vBulletin developers and he told me that they are not 100% sure what is the best solution: cache more queries or files.
For example, in vBulletin 4, you will be able to cache the templates as files, on the vBulletin datastore, or directly with memcached.
That is quite ingenious, since you have the liberty to use whatever method suits best your forum.

Please guys, comment more on this issue. Your opinion is important to me.

Floren