I purchased the dock, and the transformer because I wanted to be able to use the single item that I carry with me, for everything.
The TF700, which started out with the TF201 for me, is an amazing tablet in it's own right. Plenty of power, a crystal clear screen, and no excess crap thrown into it as a skin.
The dock, which is the same one from my TF201, is the best accessory in the world. It gives me extra battery life, which means that since the day I've purchased it, I haven't ever had to charge it mid-day. The extra SD card slot lets me put another 128gb of storage onto it, which using the keyboard dock as a stand, is perfect for watching movies, and the Pinky & The Brain episodes that I've put on it. If I ever need to take notes, work on a project, or use splashtop to remote into my computer, I have the full function of a keyboard, without anything missing.
I didn't purchase this in place of a netbook, instead I purchased it as a compliment to my laptop. But I've found that since I had the Transformer, I haven't used my laptop at all on the road. So I've given up, started carrying a smaller bag, and am perfectly content with my TF700 and dock.
I started my tablet career out with the Motorola Xoom. A tablet which I loved dearly. I purchased many accessories for it, but none compared to the functionality of the Transformer series dock. I haven't bothered to root my TF700, and with Volume+ working on it perfectly fine, I don't need any extra speakers to go with it at all.
Oh, and the full USB port? Yeah, that works perfectly with my external hard drive. I wasn't sure it would have enough juice to power it, but it works so amazingly! I'm still waiting on my friend for a PS3 controller to go with it all.
I'm sorry, I forgot that my intelligence is no match for your ignorance.