I've always used Motorola products and have never had anything over 10 seconds (max) for startup time. I'm now using a replacement phone from Kyocera which I have no complaints about so far; it starts up in about the same time if not faster.
I'm thinking about switching from Alltel (formerly GTE) to Nextel, though I must say that my coverage is phenominal with Alltel. I can travel through the Everglades and sustain a signal the whole trip.
I am also fond of the vibrate feature. It doesn't intrude on anything you are doing and if you ignore it, the only one that knows is you. The person calling just thinks you forgot your phone somewhere and you call back when you have time.
It really isn't that hard to ignore a cellphone or any other electronic device for that matter. I laugh when I see people run around or jump over furnature to answer a phone.