As some of your opinions,the former one may be better as the parasitic capacitance concerned.
I was just not sure if this would misfunction.
Now can you please tell me to what extent the former one is used. Can I use it instead of the latter
wherever the multipliers exist?
First schematic have 7 nets, second one have 6 nets. There are rules for LVS which allows them to be similar. The first is easier to layout because it does not require one connection. If the application is a cascode current source also mismatch is not improved because it is defined by the lower part. All other effects does not differ.
In terms of nosie, I have calculated it, no mater the flicker noise or thermal noise,
the two cases are with the same noise. Very clever, rfsystem, how do you get
this knid of intuition?