Well Bluff,
I'm in the same dilemma, so are a LOT of people. Bit vs. Digi threads are everywhere!
Anyway, I personally went with the Digi (at first, now I'm buying BOTH and will likely soon buy the MiniZ cars too!

)
Once I have all my toys together (bit and digi that is, Mini I'll do later), I'm going to do an ALL OUT comparison between the 2 and post my results on my webpage (or maybe Tiny might put my article on TinyRC.com even!

)
That might be a couple of weeks in the making though, as I have to wait for everything to arrive.
1 bit of advise I will give you though...
- If you decide to buy DigiQ, DON'T buy a kit with the regular Digi Propo controller. Instead buy the Digi Propo Special controller (it has a programmable LCD screen for MUCH BETTER manual settings) and just a car. A LOT of people that I've read about who've bought Digis and then upgraded to the new controller like the new options MUCH better...So save yourself some money upfront!
- Also, if you decide on Digi...Buy 2 cars! The charge on a Digi lasts 15 minutes per run, but it takes 10 minutes to recharge...With 2 cars, you can run 1 while the other is being charged on the charger! For CONTINUOUS playing!
- If you decide on a Bit, get one with a 2.2 motor. Again, from a lot of the posts I read, the 2.2 is the SWEET SPOT for speed and control. The 1.0 motor that comes in a lot of packages are just WEAK and the 3.0 is just TOO FAST to be able to handle properly...The 2.6 motors are nice too, but by and large I've been reading that 2.2 is jussssst right.
Oh, and stop on by my webpage...I've created an all inclusive chart for BOTH the Digi and Bits (with pics) so you can see what's available and in what ID/Frequencies and such too!
Good luck in whichever way you go!