There is no denying the popularity and in turn richness of WordPress.
It is the only Wiki/Blog software with professional looking themes and a strong community of exports who can customize WordPress.
Requirements
- Allows multiple sites
Research
Multiple Sites
Start of multiple blogs instructions states that,
If you want multiple blogs using WordPress, you must actually install each separately (that is, as a separate WordPress installation). You can do this whether you have the ability to create multiple databases or are limited to a single database.
Please note in WordPress 3.0 there is now a native ability to create multiple blogs, referred to as a network of sites. This is because the codebase for WordPressMU was merged into core. See Create A Network.
Now, which method is better?
Separate
Well looks pretty straightforward.
Multisite Network
From Before You Create A Network, it has the following features,
- Can do different domains, subdomains or paths
- This is confusing but the message is that WordPress refers to domains and sub-domains the same thing, sub-domains. "A sub-domain install creates a domain-based network, even though you might use separate domains, and not subdomains, for your sites."
- You can have separate databases or use the same with different table names
- There is only on instance of WordPress to maintain
Cons,
- Wordpress works differently
- Relatively newer concept and plugins often not written in mind
- Performance gain is negligible
Conclusion
Will go with separate self contained installs as the performance gain is negligible. Wordpress upgrades are straightforward so the maintenance gains are also negligible.