Do I like it? Here is how I would rate the Jetbook :
On scale of 1-10, 10 being my idea of the ultimate reader, I would rate the Jetbook a 7. However, among the current reasonably priced readers (i.e. excluding iRex which on paper has most features I would desire) I would rate it a 10 out of 10 due to its superior screen, price and feature set. Although the software can be a little rough around the edges I know that the company is actively improving it.
Its nearest competitor, the Sony 300 is higher priced (street price, that is) and its sloooooow software is lacking basic functionality that the Jetbook has in spades. Need I mention its screen is vastly inferior in contrast level relative to the Jetbook, which has a brighter background (hey it is reflective, isn't it?) and really black text. And lastly all the e-ink devices have those long, horrid blackouts during page changes while the Jetbook changes pages almost instantly. How could I not like it?
PS About the slider, I rarely use it myself, but I think the feel of its movement could be improved.