TRANSISTOR Disadvantages-MOSFET Advantages

Hi friends,this time i wanna talk about basic electronic devices, they are transistor and mosfet with their disadvantages and advantages respectively. Major disadvantages that i would consider for transistor are,
1.Input impedence
2.Stability
I would also explain how these two are advantages for mosfet.
1.Input impedence : 
For transistor:Any small input at the base terminal will turn transistor active and make it work (i.e as a amplifier or as a switch),which is not required at particular small input. Transistor should respond only to a reasonable input .This indicates the input impedence(Ri) of a transistor is low.Actually for CC based transistor configuration,the input impendence is upto 500k ohms,which is enough, but if transistor is biased then due to R1 and R2 the net input impedence will decrease(R1||R2||Ri).
For mosfet:Mosfet abbreviates metal oxide semiconductor field effect transistor,as the name itself indicates presence of oxide(SiO2) an insulator,which  prevents mosfet not to respond for small inputs
2.Stabilty
For transistor:We desire a fixed operating point that to in active region with Ib,Ic,Vce.The flow of small current(due to low input impedence) into BJT results in dissipation of electrical energy inform of heat.This results in rise of tempoerature which inturn increases Ic0 but Ic=(alpha)IE+Ic0,so Ic also increases.With this operating point is disturbed.It is referred as bias instability.To overcome bias instability,we have bias circuits which will stabilise the Q pont even change occured in Ic0 and temparature.Ic0 increases by 2 times for every 10 degree rise in temperature.
For mosfet:Bais instability is occured in BJT due to low input impedence,but as i said mosfet has high input impedence(due to SiO2) compared to transistor,so chances of instability is less in case of mosfet.