After a day of using the RK-9000, I can say that it is definitely the best keyboard I've ever typed on. The couple of problems I had with it in part 1 of my review have cleared up. There have been no more issues with sticking keys, and I've gotten used to the smaller keyboard size. The smaller size has actually increased my typing dexterity and speed.
I've been using http://typeracer.com to calculate my overall WPM speed. I started our around 58, which is a bit low for me. Since then, I've brought my average typing speed up to around 75wpm which is about the same as my Unicomp average. However, I've spiked on some races with 89wpm, and it's not uncommon for me to hit over 80wpm in a race. This is faster than my Unicomp speeds. I think the speeds will gradually increase as I become more accustomed to using the RK-9000.
Overall, this may be the best $100 my sister has ever spent on me. The keyboard is an absolute joy.