Lots of apples vs oranges in this thread...
 
Heed the advice of "...make a list of features you want..."
Some things that many don't think about:
- Rack mount vs. desktop
- Back connectors vs front
- How many preamps do you want?
- Dedicated headphone outputs? how many? 
- Physical controls that are easy to access (preamp gain, monitoring volume, Line/Mic switches, Metering, ...)
 
Once you get to the level discussed here, the preamps are good, but they do have 'personality'. You can always collect outboard preamps over time and run them into the A/D at line level. 
 
Lots of options if you're starting with a clean slate. I'm lucky as I like the sound of the Focusrite preamps, and I have a few discrete tube preamps for special stuff. 
 
Read about which brands keep up with good drivers. I had a lot of trouble with M-Audio drivers, for example, although they may be better now. This is important...no matter how nice it sounds, if it is erratic, you won't be as productive.

Cactus Music
I always say make sure the interface you buy meets your present and future needs. Make a wish list of features and stick to it while shopping. 

 
I just ordered a MOTU UltraLite-mk3 Hybrid to replace my Quad Capture.  I want an interface with more I/O, but I need the smaller footprint too.  MOTU is consistently top-rated and the price fit my budget.  I was looking at several and couldn't decide until I read this thread again and JV's comments.
 

Didn't see if you're Windoze or fruit. If so, Apogee has a new Element range, supposedly up to regular Apogee standards, which are the highest in the business. Check the other thread.

eph221
What's the current state of USB 3?  If you do a search some people say it's only necessary for a bigger pipe rather than flow, and others say it makes a big difference on latency.  Like what's the story on the zoom uac-2?

An audio interface with 24-channels of I/O is nowhere near saturating the bandwidth of USB-2.
Thus, simply increasing the bandwidth doesn't increase performance.
 
The only way to best the round-trip latency of the latest MOTU AVB series (when connected via USB-2) is to run a PCIe or Thunderbolt (running "PCIe via Thunderbolt") audio interface.