I've swapped to cab forward on a 1/10th 4wd (B44.1) and 1/16th micro 4wd (GT14B)...and in both cases the car just felt more stable and planted...
...I was a complete cab forward hater (and visually still am to some degree, although I'm more used to it now) and had originally put my old B44 shell on the new B44.1 when I got it as a result! But I can't argue with what I felt when I changed to the new kit cab forward shell to try it out and see!
I can't say as I noticed a dramatic steering change/increase as such, but the added stability certainly makes turn in (and the car in general) more predictable at speed, which might give the result of being able to more confidently throw the car around...and allow you to use more steering. If you see what I mean?!?!?
I'm not sure it's actually improved my fastest lap times either necessarily...but I do think it's helped with consistency, which over 5 mins of racing...I'll take any assistance I can
And in the end improved consistency will improve confidence...and then laptimes will hopefully follow from that!
My personal thought is it's just cleaned the aero up generally...the rear wing is now more effective, which must help keep the back end in place better at speed, and the front face of the cab is closer to the front shock tower which must reduce the turbulence the tower creates, keeping the front end in check more. But I'm no aero expert so that is just a marginally educated guess!
Now very tempted to change my S2 style shell (that I love to bits!!!) on the C4.1 for a cab forward shell to see if it helps that one. My gut says it'll probably effect the 2wd even more as the car is generally lighter upfront on a 2wd...we will see soon enough I suspect!