The network effect is extremely important, and the brand name too ... those are the two major reasons why Bitcoin has a higher value than other alts, hence I'm against the forkings. At the other hand, from my point of view, Bitcoin is a dead end by now, the user experience is horrible due to the capacity limit, and there is no longer any hope to get that lifted - it's mostly valuable now as a speculative asset class - aka "digital tulips". To preserve cryptocurrency we need some other coin to take over its role.

Here is my take on the forks:

• Bitcoin Cash. It aims to "preserve the Satoshi vision of a peer-to-peer electronic cash system". It's not hard to see that the "incumbant" Bitcoin fails on this. I was initially against Bitcoin Cash because I saw it as just "yet another altcoin", if one is hoping for "the flippening" it would be better to back one of the existing altcoins, one that has clear advantages over Bitcoin. However, Bitcoin Cash is growing the network effect, maybe it will overtake the "incumbant" Bitcoin at some point.
• Bitcoin Gold. All my criticism against Bitcoin Cash is valid against Bitcoin Gold. I early on thought that Bitcoin Gold wasn't not to be taken serious. Bitcoin Gold aims to tackle the mining centralization, but I'm not convinced they will succeed with that in the long term, and there are many other coins trying to do the same with various success. There are many other reasons to dismiss Bitcoin Gold. I could be wrong though, after all I cannot deny that it actually do have a significant market value.
• Bitcoin Diamond ... that's the biggest nonsense of those three projects. But I could be wrong on this one too, just like I've been wrong on the first two ones.