I've found in the LX's (which is the only car I've been driving recently) that yes in fast corners at 100mph/4th gear (or whatever) the rear end wants to step out even with smooth controls.
But I think that's 100% accurate. You can't make the tyres generate more grip just by being gentle - at some point you WILL exceed the limit of grip. And then you just recover it. As for the oversteer/understeer balance, I think it's partly because all LFS setups are setup for faster but riskier oversteer, and partly because you can't feel the oversteer building up though your seat.
So in terms of grip, and grip loss I think LFS is pretty close. Having opposite locked my F3 car at 90mph I think it's a fair comparison. But LFS still loses/regains traction (once it's lost, which isn't far off) a bit too gradually... Again, my F3 car is on 'forgiving' crossplies, yet still snaps a lot. Radials would make this fine line between grip and slip even finer.
Scawen has already stated he doesn't consider the tyre model 'finished', and there is no doubting it's better than it was. A few tweaks here and there (and I firmly believe it is just a few tweaks, albeit perhaps tricky, time consuming tweaks), and it will be very very good.
Regardless, there is NO OTHER SIM that gets close to LFS's feel or accuracy on tarmac. rFactor forgot to include the physics engine, Sinbin found it too complicated and simply deleted the 'Physics' folder, and nKP might have superlative tyres but no one can load the software for long enough yet to find out... If you don't like LFS then you either don't know what driving a car is really like, or you don't care about the driving and just want lens flare...