All out speed won't win you races. When i first started I accidentally cut the first hairpin, met the rest of the field coming head on, took myself out and two others in a quality pile up. Car was just too fast for me as a first timer and that was a Bosscat 4WD with a 27single motor and a brick sized Nosram ESC
Personally i'd stick with the Losi that you have, they're decent cars and are frequently up there in national A finals, so they can't be all that bad can they? If you really want to change, then get the cat sx, otherwise as someone else mentioned you'll have to buy saddle pack for ya b44, then again, i'm assuming your running LiPO?, if not then cat nicad's are a 4x2 config so that bit of advice is obsolete..
slow the car down, that will probably do you more good and give you more faith in the losi. learn how all the settings on the car affect the handling.. What exactly is it you don't like about the xxx4? understeer, oversteer?? maybe we can suggest ways of making your car better suited to your driving. a naff setup on a b44 won't be any better than a naff setup on the losi.