Direct follow? Well... more or less so. You can 'define' what happend in first game here via dialogues, though no major change if my memory serves right. Also - yes, you can be bad. That choice is always present. :)
Generally... the construction of the plot is different - I would dare to say that first game, while I really enjoyed it, was a bit cliche, while I didn't feel like that with Kotor 2. Of course it's also a matter of taste - some people enjoyed the first game more, while others prefer the second one. You still go from planet to planet, in your own order, finishing their respective plots to advanced towards the final mission... so I would say give the game a go. You shouldn't be disappointed.
That's great, thanks for your input. I recently bought the Star Wars Humble store bundle so have been considering which Star Wars game to play next. If KOTOR 2 wasn't rated as highly as the first then I might have waited a while to start it but it sounds as if I'm going to enjoy it at least equally so I think I'll jump straight in. Thanks again.