Hi Dikki
All valid points, and yes most will have a computer, however most of them keep them separate, (EG. They show off there keyboard but hide their computer) as to sequencers on computers, you will find most arranger uses aren’t interested, likewise hard disc recording, but what they do like is to be able to press a button on there keyboard, and start recording, and with another button press, play it back. (They are mainly not interested into how much better it would be to use the computer)
Remember USB 1.1 is not much quicker then typical modern broadband connections, and compared to USB 2 is excruciatingly slow.
The memory used in your Kurzweil is not that large as it is used solely for producing a few sounds, (Although even with today’s large sample VSTs I still think Kurzweil produce the best Piano and String sounds) and this is why it loads fast.
As to features, some like it nice and simple whereas others want all the bells and whistles, and so manufactures have to try and satisfy all camps. (Jack of all trades)
BTW Are you on Skype
Enjoy whatever you play

Bill