That all depends on your needs... Ask yourself what you with your Nook Color...
Is it primarily for reading books or are you using it as a full-fledged tablet?
If you used ManualNooter, then you'll see some similarities with the options that were unlocked in your Nook Color.
If you are looking to use apps, you may not be as impressed with the NTab at launch - it has the same app limitations as a stock NC. (No sideloading apps at present.) Perhaps that will change with NTab user demands, but only time will tell...
Do you watch a lot of video on your NC? If so, then you might like the NTab more, as the screen quality has been bumped up quite a bit. So far, it still only handles the same video formats as the Nook Color, but the screen and GPU are much more powerful, yielding a much richer video playback experience overall.
(I'm talking about playing mp4 encoded video files off a microSD card - YouTube and Netflix streaming aren't as important to me as using the NTab as a media player, so I can't speak for HD streaming via 'the web'.)
The speed of the NTab is the most impressive thing - It is *VERY* fast.
Pop into your local Barnes and Noble and test drive it - it's a completely different device than a stock or rooted Nook Color. You'll get that within minutes of testing it out.