I have yet to find a keyboard where the process for live playing is much more than "Turn on the keyboard, pick a sound in a fairly straight-forward manner, and play the keys". I *strongly* suspect people who feel the average workstation keyboard is too difficult either:
a) get scared at the sight of buttons and knobs that they don't understand
b) feel that they need to understand every feature on the keyboard in depth to make it worth having, and don't want to put the time in to learn
c) don't realize that it can take years of work to understand keyboards and synthesis in-depth and get frustrated when it doesn't happen in minutes or hours.
When I was shopping for a keyboard this past December (and ended up buying the Korg TR) and I went into stores to try out various models, I was able to sit down at any keyboard I liked, regardless of manufacturer and my experiences with that brand before, and figure out in a matter of seconds both how to go to the next and previous preset and how to pull up and pick from a list of presets in a category, if the keyboard had that feature. As long as I knew that the keyboard satisfied my tech requirements in some manner (which, from searching for the right things in the manuals, I knew ahead of time - I *didn't* use the manuals to tell me how to pick sounds from a category or switch sounds period), *all* I cared about in store was action and sound. I completely ignored any advanced features and just played it.
Would it be easy to figure out how to operate the sequencer on a Korg or Yamaha in-store without a manual? Maybe not, but I didn't care because I primarily play at church and didn't need to worry about learning extra capabilities until I needed them. Greg is probably in the same position: he wants good sound with a small learning curve, and I can say with certainty that as long as you can ignore things you don't need to use, the very basics of live playing is completely trivial.
I don't believe that anyone capable of learning to play keyboard parts with both hands can't figure out how to switch sounds on any keyboard on the market today. That may be the only thing they care to do, and they may not do it in the best way (i.e. entering the three-digit program number by hand to switch presets instead of reorganizing presets so they're in a logical order), but they can do it.
When it comes to buying a keyboard with a tone generator, the primary decision factor, other than cost vs. budget, should be "Does it make the sounds I want, and how well does it do so compared to the competition", unless you have other very specific factors (i.e. "I can't integrate it into my setup unless it has MIDI THRU as well as MIDI OUT", or "I need a keyboard that supports a switch pedal to increment the current program"). Buying for simplicity will give you just that: something that's simple in use and simple in sound. If that's really all you want, fine; if not, be prepared to master using arrow keys and/or category buttons to pick your sounds, all of which you'll find out in the Quick Start guide that most keyboards nowadays have.