tascam or M-audio?

Right now i have a presonus Firebox, and i am looking to upgrade to one of these (M-audio/Tascam). Would it be safe to say that the quality of the preamps in the M-audio or tascam would be better them my current Firebox set up? Basically am i going to be able to get a better sound out of ones of these? If not its not really an upgrade to me.

Any opinions?
 
I'd probably go for the project mix, mostly for the LCD displays. Without them, it's not immediately apparant which fader controls which track. That said, M-Audio driver support isn't that great, particularly for 64-bit OSes.
 
I own the Tascam and I'm also using it with Cubase (SL3). It's a nice unit for a hobbyist like me, but there are some issues that are bugging me:
- Tascam driver update policy
- driver instability
- the Mackie HU emulation doesn't really work out of the box. For example, I can't use the console EQs in Cubase because the EQs are controlled by the pan knobs (!) (probably there's a way to re-program it, but that's not how you want to spend your weekends).

I got it second hand for a good price, and since I'm just recording for my private pleasure it works well for me. The preamps sound good to me (compared to the USB-interface I had before), but I can't compare it to another preamp of this price range.

The display of the M-Audio will definitely be a plus.

You could consider buying a good stand-alone interface (RME, Presonus etc.) and additionally a controlling unit like the Mackie Control or even a simple Behringer one. (I found out that I basically use just the faders and the transport functions on the Tascam and still do most of the work with the mouse within Cubase. But then again, I'm just a hobbyist.). I think, that's the way I'd go today.