Pinside has got a lot of things going for it, but it isn't number one in at least a few fields;
- IPDB still is the the number one resource for background information and/or machine pictures.
- Pinballhead.com has become the best source for pinball related news, as it is often the fastest and most complete.
- the old pinrepair.com documents still are my first stop for general technical information. A lot of people probably have a local copy or found a mirror that still works. Pinwiki is on the rise though, and becomes increasingly valuable, although progress has been slow.
What makes Pinside special though, is that it is the only site which provides an integrated experience. It also is under active development, in contrast to IPDB for example.
Maybe there's a future in working together with sites like ipdb, pinwiki and pinballhead instead of creating redundancy. I'm pretty sure most sites are operated out of love for the game, which could prove to be a good foundation for some kind of collaboration.