Anyone using these without the help of a piggy back? Are there any problems?

Shouldn't have any problems, as long as you have a decent air fuel gauge and fuel pressure gauge to tune it. I had an sfmu with 360's and didn't have much of a problem (was on friends eclipse that I helped with). Piggy back just helps "fine-tune".

Sfmu will definately get you in the "ball park"

With the 440's, i would highly suggest you use a SAFC with the SFMU. To not run real rich and throw a CEL at idle, you need to run like 11-15 psi of fuel pressure at idle, and with that low of pressure, the car may not run very well. It would be best to up the fuel pressure to the point of where it will idle decent, then use the SAFC very sparingly, as in no more than +/- 10% adjustment. IMO, a good medium is to run the 390cc injects. No SAFC would be needed, and thats enough fuel to run around 16-17 psi safely on the S16G turbo. You can prob get away with 415's and SFMU only, but thats pushing it..I suppose you can always try out the 440's and SFMU alone, and see what happens, but i will bet it will run way too rich, even running super low fuel pressures..