The Good: The Fit Wifi frame in 20.75" is my current frame and unless it breaks, it will be my frame for a long time, I may even get another after this one. I primarily ride street and park , and with the shorter rear end length and steeper head-tube angle of the WiFi I've found it very quick and responsive, without being squirrelly. This is a very durable frame and has yet to show any concerning signs of wear, (for example I bounced the DT off a ledge pretty hard yesterday and it barely dinged it). The geometry of the WiFi is what stood out to me most and is the main reason I bought it, also the price is very reasonable on them. I like the shorter rear end more for ease of getting up onto bar/over bar height ledges and rails, for me it's easier to suck up the rear end on a shorter frame, but also it's been great for spins and manuals without having too much a tendency to get loopy.
The Bad: Not made in U.S.A.... That's about all I can find that I don't like , but it also would've made the frame more expensive to make it here so it's really not an issue! Maybe some more color variety would be cool too!
If you're in the market for a strong, responsive light (sure there are lighter frames but at under 5lbs if you think that's heavy....nvm) then get a WiFi. You'll save a bunch of money and be happier than you would with whatever else you were lookin' at! They're strong, quick, stiff and well priced. Can't go wrong with the Fit WiFi!