You're obviously frustrated. I can understand this, but ultimately I believe you may be asking questions that will not yield the answers you seek. All manufacturers will tell you they have a great system, but I would recommend that you visit some editors who are using some of the available systems and see how well they work and if you, personally like the interface and working methods.
Different editors have different favorite systems for how they personally work.
As far as processor speed, buy the most you can buy. I don't care what you're buying Mac, Windows or NT, buy all the processor speed and RAM you can afford. You've probably heard this before and it's frustrated you because it isn't a number. That can't really be helped. Most new computers can do the job.